Amphenol (APH) 424B3Prospectus supplement

The accompanying prospectus provides you with a general description of the senior debt securities, and this prospectus supplement contains specific information about the terms of this offering of the notes. This prospectus supplement, or the information incorporated by reference in this prospectus supplement or the accompanying prospectus, may add, update or change information contained in the accompanying prospectus. If information in this prospectus supplement, or the information incorporated by reference in this prospectus supplement, is inconsistent with the accompanying prospectus, this prospectus supplement, or the information incorporated by reference in this prospectus supplement, will apply and will modify or supersede that information in the accompanying prospectus.

Before making your investment decision, you should read and carefully consider this prospectus supplement and the accompanying prospectus, together with the additional information in the documents referred to in the sections entitled “Where You Can Find More Information” in the accompanying prospectus and “Incorporation of Certain Information by Reference” in this prospectus supplement.

Unless otherwise stated, or the context otherwise requires, references in this prospectus supplement to “we,” “us,” “our,” “Amphenol,” “APH” and “the Company” are to Amphenol Corporation and, as applicable, its consolidated subsidiaries, except for purposes of the description of the notes included in this prospectus supplement and the accompanying prospectus, where references to such terms refer only to Amphenol Corporation and do not include Amphenol Corporation’s subsidiaries. When we refer to the “notes” in this prospectus supplement, we mean the notes being offered by this prospectus supplement, unless we state otherwise.

This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein, include forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and the provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Such forward-looking statements are based on our management’s assumptions and beliefs about future events or circumstances using information currently available, and as a result, they are subject to risks and uncertainties. Forward-looking statements address events or developments that Amphenol Corporation expects or believes may or will occur in the future. These forward-looking statements, which address the Company’s expected business and financial performance and financial condition, among other matters, may contain words and terms such as: “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “forecast,” “guidance,” “intend,” “look ahead,” “may,” “ongoing,” “optimistic,” “plan,” “potential,” “predict,” “project,” “seek,” “should,” “target,” “will” or “would” and other words and terms of similar meaning.

The notes will constitute a new issue of securities with no established trading market. We do not intend to apply for listing of the notes on any securities exchange or quotation of the notes on any automated dealer quotation system. We cannot assure you as to the development or liquidity of any trading market for the notes. The underwriters have advised us that they currently intend to make a market in the notes, as permitted by applicable laws and regulations. However, the underwriters are not obligated to do so, and any market-making with respect to the notes may be discontinued at any time without notice. If no active trading market develops, you may be unable to resell your notes at any price or at their fair market value.

The condition of the financial markets and prevailing interest rates have fluctuated in the past and are likely to fluctuate in the future. Such fluctuations could have an adverse effect on the price of the notes.

In addition, credit rating agencies continually review their ratings for the companies that they follow, including us. The credit rating agencies also evaluate the industries in which we operate as a whole and may change their credit rating for us based on their overall view of such industries. A negative change in our rating could have an adverse effect on the price of the notes. Therefore, we cannot assure you that you will be able to sell your notes at a particular time or the price that you receive when you sell your notes will be favorable.

We may be able to incur substantial indebtedness in the future. The terms of the indenture governing the notes will not fully prohibit us from doing so. If we incur any additional indebtedness that ranks equally with the notes, the holders of that debt will be entitled to share ratably with the holders of the notes in any proceeds distributed in connection with any insolvency, liquidation, reorganization, dissolution or other winding up of the Company.

incur certain liens;

enter into certain sale and leaseback transactions with respect to any of our Principal Property (as defined under “Description of Senior Debt Securities — Definitions” in the accompanying prospectus);

consolidate or merge with or into, or sell substantially all of our assets to, another person;

make accounting changes, except as required or permitted under generally accepted accounting principles;

make a material change to the nature of our business; and

engage in speculative transactions.

In addition, case law suggests that, in the event that incumbent directors are replaced as a result of a contested election, issuers may nevertheless avoid triggering a change of control under a clause similar to third bullet of the definition of “Change of Control” under the caption “Description of the Notes — Change of Control” in this prospectus supplement, if the outgoing directors were to approve the new directors for the purpose of avoiding the triggering of such change of control clause.

We have the right to redeem some or all of the notes prior to maturity, as described under “Description of the Notes — Optional Redemption” in this prospectus supplement. We may redeem the notes at times when prevailing interest rates may be relatively low. Accordingly, you may not be able to reinvest the redemption proceeds in a comparable security at an effective interest rate as high as the interest rate of the notes being redeemed.

The notes will be unsecured and effectively subordinated in right of payment to any future secured indebtedness to the extent of the assets securing such indebtedness. Although the indenture limits our ability to incur liens on our Principal Property (as defined under “Description of Senior Debt Securities — Definitions” in the accompanying prospectus), the notes will be effectively subordinated to any future debt secured by Principal Property to the extent permitted by the indenture or secured by any of our other assets. In the event of our liquidation or insolvency or other events of default on any such secured debt or upon acceleration of the notes in accordance with their terms, we will be permitted to make payment on the notes only after any such secured debt has been paid in full. After paying any such secured debt in full, we may not have sufficient assets remaining to pay any or all amounts due on the notes. In the event of our bankruptcy, liquidation or reorganization or upon acceleration of the notes, payment on the notes could be less, ratably, than on any such secured debt.

The notes will be structurally subordinated to any indebtedness of our subsidiaries. Our subsidiaries are separate and distinct legal entities, and none of our subsidiaries will guarantee the notes or otherwise have any obligations to make payments in respect of the notes. As a result, claims of holders of the notes will be effectively subordinated to the indebtedness and other liabilities of our subsidiaries. In the event of any bankruptcy, liquidation, dissolution or similar proceeding involving one of our subsidiaries, any of our rights or the rights of the holders of the notes to participate in the assets of that subsidiary will be effectively subordinated to the claims of creditors of that subsidiary, and following payment by that subsidiary of its liabilities, the subsidiary may not have sufficient assets remaining to make payments to us as a shareholder or otherwise. As of December 31, 2022, our subsidiaries (other than Amphenol Technologies Holding GmbH, the issuer of the 2026 Notes and the 2028 Notes, which are guaranteed by us) would have had approximately $32.3 million of indebtedness to which the notes would have been structurally subordinated.

In addition, certain of our subsidiaries are guarantors under our revolving credit facility. Accordingly, the notes will be structurally subordinated to such subsidiaries’ obligations to guarantee our indebtedness under our revolving credit facility.

The notes are exclusively our obligations. Our cash flow and our ability to service our indebtedness, including the notes, is partially dependent upon the earnings of our subsidiaries. In addition, we are particularly dependent on the distribution of earnings, loans or other payments by our subsidiaries to us. Our subsidiaries are separate and distinct legal entities. Our subsidiaries will have no obligation to pay any amounts due on the notes or to provide us with funds for our payment obligations, whether by dividends, distributions, loans or other payments. In addition, any payment of dividends, distributions, loans or advances by our subsidiaries to us could be subject to statutory or contractual restrictions. Payments to us by our subsidiaries will also be contingent upon our subsidiaries’ earnings and business considerations. Our

for any registration of transfer or exchange of notes, but we or the trustee may require payment of a sum sufficient to cover any transfer tax or other similar governmental charge payable in connection with such transfer or exchange.

Notice of any redemption will be mailed at least 15 days but not more than 60 days before the date of redemption to each holder of notes to be redeemed. If less than all the notes are to be redeemed, the notes to be redeemed shall be selected by the trustee by such method as the trustee deems fair and appropriate and as long as notes are in global book-entry form, the notes to be redeemed shall be selected as determined by DTC’s applicable procedures. Unless we default in payment of the redemption price, on and after the date of redemption, interest will cease to accrue on the notes or portions thereof called for redemption.

Except as described above, the notes will not be redeemable by us prior to maturity and will not be entitled to the benefit of any sinking fund.

We may acquire notes by means other than a redemption, whether by tender offer, open market purchases, negotiated transactions or otherwise, in accordance with applicable securities laws, so long as such acquisition does not otherwise violate the terms of the indenture.

The trustee shall not be responsible for performing or verifying any calculations required in connection with a redemption.

The notes will be senior unsecured and unsubordinated indebtedness and will rank equally with all of our existing and future senior unsecured and unsubordinated indebtedness, including the 2024 Notes, the 2025 Notes, the 2029 Notes, the 2030 Notes, the 2031 Notes and the indebtedness evidenced by our guarantee of the 2026 Notes and the 2028 Notes issued by our subsidiary, Amphenol Technologies Holding GmbH, and any borrowings under our revolving credit facility. However, the notes are structurally subordinated to the indebtedness of our subsidiaries and effectively subordinated to any future secured indebtedness to the extent of the value of the assets securing such indebtedness.

As of December 31, 2022, on a pro forma as adjusted basis after giving effect to this offering and the application of the net proceeds from this offering as more fully described in “Use of Proceeds” in this prospectus supplement:

The notes will be structurally subordinated to any indebtedness of our subsidiaries. The 2026 Notes and the 2028 Notes, which are guaranteed by us, constitute our general senior unsecured obligations and rank equally in right of payment with our existing and future unsecured and unsubordinated indebtedness, including the notes offered hereby. Our subsidiaries are separate and distinct legal entities, and none of our subsidiaries will guarantee the notes or otherwise have any obligations to make payments in respect of the notes. As a result, claims of holders of the notes will be effectively subordinated to the indebtedness and other liabilities of our subsidiaries. In the event of any bankruptcy, liquidation, dissolution or similar proceeding involving one of our subsidiaries, any of our rights or the rights of the holders of the notes to participate in the assets of that subsidiary will be effectively subordinated to the claims of creditors of that subsidiary, and following payment by that subsidiary of its liabilities, the subsidiary may not have sufficient assets remaining to make payments to us as a shareholder or otherwise. In addition, certain of our subsidiaries are

We are obligated to pay reasonable compensation to the trustee and to indemnify the trustee against certain losses, liabilities and expenses incurred by the trustee in connection with its duties relating to the notes. The trustee’s claims for these payments will generally be senior to those of holders of the notes in respect of all funds collected or held by the trustee.

Within 30 days following any Change of Control Repurchase Event, or at our option, prior to any Change of Control but after the public announcement of the pending Change of Control, we will send, by first class mail, a notice to each holder, with a copy to the trustee, which notice will govern the terms of the Change of Control Offer, stating:

The trustee will promptly mail, or cause the paying agent to promptly mail, to each holder of notes so tendered, the Change of Control Payment for such notes, and the trustee will promptly authenticate and mail (or cause to be transferred by book entry) to each holder a new note equal in principal amount to any unpurchased portion of the notes surrendered, if any, provided that each such new note will be in a principal amount of $2,000 and integral multiples of $1,000 in excess thereof.

If the Change of Control Payment Date is on or after an interest record date and on or before the related interest payment date, any accrued and unpaid interest, if any, will be paid to the person in whose

Except as described above with respect to a Change of Control Repurchase Event, the indenture does not contain provisions that permit the holders to require us to repurchase or redeem the notes in the event of a takeover, recapitalization or similar transaction.

We will not be required to make the Change of Control Offer upon a Change of Control Repurchase Event if a third party makes an offer in the manner, at the times and otherwise in compliance with the requirements set forth in the indenture applicable to the Change of Control Offer made by us and repurchases all notes validly tendered and not withdrawn under such offer.

We will comply, to the extent applicable, with the requirements of Rule 14e-1 under the Exchange Act and any other securities laws or regulations thereunder to the extent those laws and regulations are applicable in connection with the repurchase of the notes as a result of a Change of Control Repurchase Event. To the extent that the provisions of any such securities laws or regulations conflict with the Change of Control Offer provisions of the notes, we will comply with those securities laws and regulations and will not be deemed to have breached our obligations under the Change of Control Offer provisions of the notes by virtue of any such conflict.

Our ability to repurchase notes pursuant to the Change of Control Offer may be limited by a number of factors. Certain events that may constitute a change of control under our other senior indebtedness and indebtedness of our subsidiaries and cause a default under the agreements related to such indebtedness may not constitute a Change of Control Repurchase Event under the indenture. Our revolving credit facility provides that the occurrence of certain change of control events would constitute a default thereunder. Future indebtedness of ours and our subsidiaries may also contain prohibitions of certain events that would constitute a Change of Control Repurchase Event or require such indebtedness to be repurchased upon a Change of Control Repurchase Event. Moreover, any exercise by the holders of our outstanding senior notes of their right to require us to repurchase their notes could cause a default under such indebtedness, even if a Change of Control Repurchase Event itself does not, due to the financial effect of such repurchases on us. Finally, our ability to pay cash to the holders upon a repurchase may be limited by our then existing financial resources. We cannot assure you that sufficient funds will be available when necessary to make any required repurchases. See “Risk Factors — We may not be able to repurchase the notes upon a Change of Control Repurchase Event.”

This discussion does not address all U.S. federal income tax consequences relevant to a holder’s particular circumstances, including the impact of the Medicare contribution tax on net investment income. In addition, it does not address consequences relevant to holders subject to special rules, including, without limitation:

If an entity or arrangement treated as a partnership for U.S. federal income tax purposes holds the notes, the tax treatment of a partner in the partnership will depend on the status of the partner, the activities

For purposes of this discussion, a “U.S. Holder” is a beneficial owner of a note that, for U.S. federal income tax purposes, is or is treated as:

an individual who is a citizen or resident of the United States;

a corporation created or organized under the laws of the United States, any state thereof, or the District of Columbia;

an estate, the income of which is subject to U.S. federal income tax regardless of its source; or

a trust that (1) is subject to the primary supervision of a U.S. court and the control of one or more “United States persons” ​(within the meaning of Section 7701(a)(30) of the Code), or (2) has a valid election in effect to be treated as a United States person for U.S. federal income tax purposes.

Interest on a note generally will be taxable to a U.S. Holder as ordinary income at the time such interest is received or accrued, in accordance with such U.S. Holder’s method of tax accounting for U.S. federal income tax purposes.

A U.S. Holder will recognize gain or loss on the sale, exchange, redemption, retirement or other taxable disposition of a note. The amount of such gain or loss will generally equal the difference between the amount received for the note in cash or other property valued at fair market value (less amounts attributable to any accrued but unpaid interest, which will be taxable as interest to the extent not previously included in income) and the U.S. Holder’s adjusted tax basis in the note. A U.S. Holder’s adjusted tax basis in a note generally will be equal to the amount the U.S. Holder paid for the note. Any gain or loss will be capital gain or loss, and will be long-term capital gain or loss if the U.S. Holder has held the note for more than one year at the time of sale or other taxable disposition. Otherwise, such gain or loss will be short-term capital gain or loss. Long-term capital gains recognized by certain non-corporate U.S. Holders, including individuals, generally will be taxable at a reduced rate. The deductibility of capital losses is subject to limitations.

A U.S. Holder may be subject to information reporting and backup withholding when such holder receives payments on a note or receives proceeds from the sale or other taxable disposition of a note (including a redemption or retirement of a note). Certain U.S. Holders are exempt from backup withholding, including corporations and certain tax-exempt organizations. A U.S. Holder will generally be subject to backup withholding if such holder is not otherwise exempt and the holder:

is notified by the IRS that the holder previously failed to properly report payments of interest or dividends; or

fails to certify under penalties of perjury that the holder has furnished a correct taxpayer identification number and that the IRS has not notified the holder that the holder is subject to backup withholding.

Any such effectively connected interest generally will be subject to U.S. federal income tax on a net income basis at the regular rates applicable to United States persons. A Non-U.S. Holder that is a corporation also may be subject to a branch profits tax at a rate of 30% (or such lower rate specified by an applicable income tax treaty) on such effectively connected interest, as adjusted for certain items.

The certifications described above must be provided to the applicable withholding agent prior to the payment of interest and may be required to be updated periodically. Non-U.S. Holders that do not timely provide the applicable withholding agent with the required certification, but that qualify for a reduced rate under an applicable income tax treaty, may obtain a refund of any excess amounts withheld by timely filing an appropriate claim for refund with the IRS. Non-U.S. Holders should consult their tax advisors regarding their entitlement to benefits under any applicable income tax treaty.

A Non-U.S. Holder will not be subject to U.S. federal income tax on any gain realized upon the sale, exchange, redemption, retirement or other taxable disposition of a note (such amount excludes any amount allocable to accrued and unpaid interest, which generally will be treated as interest and may be subject to the rules discussed above in “— Payments of Interest”) unless:

the gain is effectively connected with the Non-U.S. Holder’s conduct of a trade or business within the United States (and, if required by an applicable income tax treaty, the Non-U.S. Holder maintains a permanent establishment in the United States to which such gain is attributable); or

the Non-U.S. Holder is a nonresident alien individual present in the United States for 183 days or more during the taxable year of the disposition and certain other requirements are met.

Gain realized by a Non-U.S. Holder described in the first bullet point above generally will be subject to U.S. federal income tax on a net income basis at the regular rates applicable to United States persons. A Non-U.S. Holder that is a corporation also may be subject to a branch profits tax at a rate of 30% (or such lower rate specified by an applicable income tax treaty) on such effectively connected gain, as adjusted for certain items.

Gain realized by a Non-U.S. Holder described in the second bullet point above will be subject to U.S. federal income tax at a rate of 30% (or such lower rate specified by an applicable income tax treaty) and may be offset by U.S. source capital losses of the Non-U.S. Holder (even though the individual is not considered a resident of the United States), provided the Non-U.S. Holder has timely filed U.S. federal income tax returns with respect to such losses.

Any Plan fiduciary that proposes to cause a Plan to purchase the notes should consult with its counsel regarding the potential applicability of the fiduciary responsibility and prohibited transaction provisions of Title I of ERISA, Section 4975 of the Code or applicable Similar Laws to such an investment, and to confirm that such purchase and holding will not constitute or result in a non-exempt prohibited transaction or any other violation of an applicable requirement of ERISA, Section 4975 of the Code or applicable Similar Law. In considering an investment in the notes with a portion of the assets of any Plan, a fiduciary should determine whether the investment is in accordance with the documents and instruments governing the Plan and the applicable provisions of ERISA, the Code or Similar Laws relating to a fiduciary’s duties to the Plan including, without limitation, the prudence, diversification, delegation of control and prohibited transaction provisions of ERISA, the Code and any other applicable Similar Laws.

Section 406 of ERISA and Section 4975 of the Code prohibit Covered Plans from engaging in specified transactions involving Covered Plan assets with persons or entities who are “parties in interest,” within the meaning of ERISA, or “disqualified persons,” within the meaning of Section 4975 of the Code, unless an exemption is available. Those sections further prohibit a fiduciary from engaging in transactions in which a conflict of interest is deemed present. A party in interest or disqualified person (including a fiduciary) who engaged in a non-exempt prohibited transaction may be subject to excise taxes and other penalties and liabilities under ERISA and/or the Code. In addition, the fiduciary of a Covered Plan that engaged in such a non-exempt prohibited transaction may be subject to penalties and liabilities under ERISA and/or the Code. The acquisition and/or holding of the notes by a Covered Plan with respect to which the Issuer, any subsidiary guarantor, the underwriters or any of their respective affiliates may be considered a party in interest or a disqualified person may constitute or result in a direct or indirect prohibited transaction under Section 406 of ERISA and/or Section 4975 of the Code, unless the investment is acquired and is held in accordance with an applicable statutory, class or individual prohibited transaction exemption.

In this regard, the U.S. Department of Labor has issued prohibited transaction class exemptions, or “PTCEs,” that may provide exemptive relief for direct or indirect prohibited transactions resulting from the sale, purchase or holding of the notes. These class exemptions include, without limitation, PTCE 84-14 respecting transactions determined by independent qualified professional asset managers, PTCE 90-1 respecting insurance company pooled separate accounts, PTCE 91-38 respecting bank collective investment funds, PTCE 95-60 respecting life insurance company general accounts and PTCE 96-23 respecting transactions determined by in-house asset managers, although there can be no assurance that all of the conditions of any such exemptions will be satisfied. In addition to the foregoing, Section 408(b)(17) of ERISA and Section 4975(d)(20) of the Code provide exemptions for certain transactions between a Covered Plan and a person that is a party in interest and/or a disqualified person (other than a fiduciary or an affiliate that,

We and the underwriters named below have entered into an underwriting agreement with respect to the notes. BNP Paribas Securities Corp., BofA Securities, Inc. and J.P. Morgan Securities LLC are acting as representatives of the several underwriters. Subject to the terms and conditions in the underwriting agreement, we have agreed to sell to each underwriter, and each underwriter has severally agreed to purchase from us, the principal amount of notes that appears opposite its name in the table below:

In connection with this offering of the notes, the underwriters may engage in overallotments, stabilizing transactions and syndicate covering transactions in accordance with Regulation M under the Exchange Act. Overallotment involves sales in excess of the offering size, which creates a short position for the underwriters. Stabilizing transactions involve bids to purchase the notes in the open market for the purpose of pegging, fixing or maintaining the price of the notes, as applicable. Syndicate covering transactions involve purchases of the notes in the open market after the distribution has been completed in order to cover short positions. Stabilizing transactions and syndicate covering transactions may cause the price of the notes to be higher than it would otherwise be in the absence of those transactions. If the underwriters engage in stabilizing or syndicate covering transactions, they may discontinue them at any time.

Certain of the underwriters and their affiliates have, from time to time, performed, and may in the future perform, various financial advisory, commercial banking and investment banking services for us and our affiliates for which they received, or will receive, customary fees and expenses.

In addition, in the ordinary course of their various business activities, the underwriters and their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers, and such investment and securities activities may involve securities and instruments of ours or our affiliates. Certain of the underwriters and their affiliates that have a lending relationship with us routinely hedge, and certain other of those underwriters or their affiliates may hedge, their credit exposure to us consistent with their customary risk management policies. Typically, such underwriters and their affiliates would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the notes offered hereby. Any such credit default swaps or short positions could adversely affect future trading prices of the notes offered hereby. The underwriters and their respective affiliates may also make investment recommendations or publish or express independent research views in respect of such securities or financial instruments and may at any time hold, or recommend to clients that they acquire, long or short positions in such securities and instruments.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement and the accompanying prospectus (including any amendment thereto) contain a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

directly or indirectly, in Japan or to or for the benefit of any resident of Japan, except pursuant to an exemption from the registration requirements of the FIEA and otherwise in compliance with any relevant laws, regulations and ministerial guidelines of Japan.

to a relevant person (as defined in Section 275(2) of the SFA) pursuant to Section 275(1) of the SFA, or any person pursuant to Section 275(1A) of the SFA, and in accordance with the conditions specified in Section 275 of the SFA; or

otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or

This prospectus supplement and the accompanying prospectus is not intended to constitute an offer or solicitation to purchase or invest in the notes. The notes may not be publicly offered, directly or indirectly,

This prospectus provides you with a general description of the senior debt securities we may offer. Each time we sell senior debt securities, we will provide a prospectus supplement that accompanies this prospectus that will provide specific information about the terms of that offering and the offered senior debt securities, including the specific amounts and prices of the senior debt securities offered. The accompanying prospectus supplement may include or incorporate by reference a detailed and current discussion of any risk factors and will discuss any special considerations applicable to those securities, including the plan of distribution. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The accompanying prospectus supplement or free writing prospectus may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under “Where You Can Find More Information.” Any information in the accompanying prospectus supplement or free writing prospectus that is inconsistent with this prospectus will modify or supersede the information in this prospectus.

The registration statement we filed with the SEC includes exhibits that provide more detail of the matters discussed in this prospectus. Statements contained in this prospectus about the provisions or contents of any agreement or other document are not necessarily complete. If the SEC’s rules and regulations require that an agreement or document be filed as an exhibit to the registration statement, please see that agreement or document for a complete description of these matters.

Before making your investment decision, you should read and carefully consider this prospectus, the accompanying prospectus supplement (and any applicable free writing prospectuses), and the related exhibits filed with the SEC, together with the additional information in the documents referred to in the sections entitled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference” below. Information incorporated by reference after the date of this prospectus is considered a part of this prospectus and may add, update or change information contained in this prospectus. Any information in such subsequent filings that is inconsistent with this prospectus will modify or supersede the information in this prospectus.

We have not authorized anyone to provide you with any information or to make any representations other than those contained in this prospectus, any applicable accompanying prospectus supplement or any free writing prospectuses prepared by or on behalf of us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. We will not make an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus and the applicable accompanying prospectus supplement to this prospectus is accurate only as of the date on its respective cover, that the information appearing in any applicable free writing prospectus is accurate only as of the date of that free writing prospectus, and that any information incorporated by reference is accurate only as of the date of the document incorporated by reference, unless we indicate otherwise. Our business, financial condition, results of operations and prospects may have changed since those dates. This prospectus incorporates by reference, and any accompanying prospectus supplement or free writing prospectus may contain and incorporate by reference, market data and industry statistics and forecasts that are based on independent industry publications and other publicly available information. Although we believe these sources are reliable, we do not guarantee the accuracy or completeness of this information and we have not independently verified this information. In addition, the market and industry data and forecasts that may be included or incorporated by reference in this prospectus, any accompanying prospectus supplement or any applicable free writing prospectus may involve estimates, assumptions and other risks and uncertainties and are subject to change based on various factors, including those discussed under the heading “Risk Factors” contained in this prospectus, the applicable accompanying prospectus supplement and any applicable free writing

the designation and aggregate principal amount of the senior debt securities of such series and their authorized denominations (if other than $2,000 and integral multiples thereof);

the date or dates on which the senior debt securities of such series will mature;

the dates on which such interest will be payable or the method by which such dates are to be determined;

the record dates for payment of such interest;

any obligation to redeem or repurchase the senior debt securities of such series, whether pursuant to a sinking fund or analogous provision or at our option or the option of the holder thereof;

the period or periods within which, the price or prices at which, and the terms and conditions upon which, the senior debt securities of such series may be redeemed or repurchased, in whole or in part;

the inapplicability of any event of default or covenant set forth in the indenture relating to the senior debt securities, or the applicability of any other events of default or covenant in addition to the events of default or covenants set forth in the indenture relating to the senior debt securities;

Unless otherwise indicated in the prospectus supplement applicable to the senior debt securities of any series, in any case where the date of payment of the principal of or premium, if any, or interest on the senior debt securities of any series, including the date, if any, fixed for redemption or repurchase of the senior debt securities of such series, shall not be a “business day” ​(as defined below), then payment of principal, premium or interest need not be made on that date at such place but may be made on the next succeeding business day, and no interest shall accrue for the intervening period. A “business day” shall mean a day that is not, in Hartford, Connecticut, a Saturday, Sunday, a legal holiday or a day on which banking institutions are authorized or obligated by law to close.

The senior debt securities will be senior unsecured and unsubordinated indebtedness and will rank equally with all of our existing and future senior unsecured and unsubordinated indebtedness. However, the senior debt securities will be structurally subordinated to the indebtedness of our subsidiaries and effectively subordinated to any secured indebtedness to the extent of the value of the assets securing such indebtedness.

We are obligated to pay reasonable compensation to the trustee and to indemnify the trustee against certain losses, liabilities, expenses and certain taxes incurred by the trustee in connection with its duties relating to the senior debt securities. The trustee’s claims for these payments will generally be senior to those of holders of senior debt securities in respect of all funds collected or held by the trustee.

Unless otherwise indicated in the prospectus supplement applicable to the senior debt securities of any series and except as discussed below, we are not restricted by the indenture from:

incurring any type of indebtedness or other obligation;

paying dividends or making distributions on our capital stock; or

purchasing or redeeming our capital stock.

We are not required under the indenture to maintain any financial ratios or specified levels of net worth or liquidity.

So long as the senior debt securities of any series are outstanding under the indenture, neither we nor any Restricted Subsidiary will, directly or indirectly, issue, incur, create, assume or guarantee any indebtedness secured by a mortgage, security interest, pledge, lien, charge or other encumbrance upon any Principal

Property or upon any shares of capital stock or indebtedness of any Restricted Subsidiary (a “mortgage”), whether such Principal Property, shares or indebtedness are now existing or owned or hereafter created or acquired, unless prior to or at the same time the senior debt securities of such series are equally and ratably secured with or, at our option, prior to such secured indebtedness.

Notwithstanding the foregoing, any mortgage securing the senior debt securities granted pursuant to this covenant shall be automatically and unconditionally released and discharged upon the release by all holders of the indebtedness secured by the mortgage giving rise to the mortgage securing the senior secured securities (including any deemed release upon payment in full of all obligations under such indebtedness).

So long as the senior debt securities of any series are outstanding under the indenture, neither we nor any Restricted Subsidiary will enter into any “sale/leaseback transaction” ​(as defined below) with respect to any Principal Property, whether now owned or hereafter acquired by us or any Restricted Subsidiary, unless:

entered into prior to the time of the closing of the offering of the senior debt securities of such series;

between us and any Restricted Subsidiary or between Restricted Subsidiaries;

under which the rent payable pursuant to such lease is to be reimbursed under a contract with the U.S. Government or any instrumentality or agency thereof;

involving leases for a period of no longer than three years; or

in which the lease for the property or asset is entered into within 270 days after the date of acquisition, completion of construction or commencement of full operations of such property or asset, whichever is latest.

Notwithstanding the restrictions outlined in the preceding paragraphs, we and any Restricted Subsidiary will be permitted to enter into sale/leaseback transactions that would otherwise be subject to such restrictions, without complying with the requirements of clauses (a) and (b) above, if, after giving effect thereto, the aggregate amount of all Attributable Debt with respect to sale/leaseback transactions existing at such time that could not have been entered into except for the provisions described in this paragraph, together with the aggregate amount of all outstanding indebtedness secured by mortgages permitted by any of clauses (1) through (11) under “— Limitation on Liens” above, does not exceed 15% of Consolidated Net Tangible Assets.

We may, without the consent of the holders of any outstanding series of senior debt securities, consolidate with, sell, lease, convey or otherwise transfer all or substantially all of our assets to, or merge with or into, any other person or entity, provided that:

any manufacturing facility (whether now owned or hereafter acquired) that:

The foregoing constitute events of default whatever the reason for any such event of default and whether it is voluntary or involuntary or is effected by operation of any law or pursuant to any judgment, decree or order of any court or any order, rule or regulation of any administrative or governmental body.

If an event of default with respect to the senior debt securities of any series, other than an event of default described in clause (5) above, occurs and is continuing, then the trustee (acting at the request or direction of the holders) or the holders of at least 25% in aggregate principal amount of the outstanding

If an event of default occurs and is continuing, the trustee, in conformity with its duties under the indenture, will be required to exercise all rights or powers under the indenture at the written request or direction of any of the holders, provided the holders provide the trustee with a security or indemnity against the costs, expenses and liabilities that might be incurred by it in compliance with such request or direction. Except to enforce the right to receive payment of principal, premium, if any, or interest when due, no holder of senior debt securities of any series may pursue any remedy with respect to the indenture or the senior debt securities unless:

such holder previously notified the trustee that an event of default is continuing;

the holders of at least 25% in aggregate principal amount of the outstanding senior debt securities of such series requested the trustee to pursue the remedy;

such holders offered the trustee reasonable security or indemnity against the costs, expenses and liabilities that may be incurred by it in compliance with such request;

the trustee has not complied with the holder’s request within 60 days after its receipt of such notice, request and offer of security or indemnity; and

the holders of a majority in principal amount of the outstanding senior debt securities of such series have not given the trustee a direction inconsistent with the request within the 60-day period.

Generally, the holders of a majority in principal amount of the outstanding senior debt securities of a series are given the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or of exercising any trust or power conferred on the trustee with respect to the senior debt securities of such series. The trustee, however, may refuse to follow any direction that conflicts with law or the indenture or that the trustee determines is unduly prejudicial to the rights of any other holder of senior debt securities of such series or that would expose the trustee to personal liability.

If a default or event of default with respect to the senior debt securities of a series occurs and is continuing and a responsible officer of the trustee has notice thereof, the trustee must mail to each holder of any debt security of such series notice of the default or event of default within 90 days after it occurs, or if later, after a responsible officer of the trustee has notice of such default or event of default. Except in the case of a default or event of default in the payment of principal, premium, if any, or interest on any debt security of such series, the trustee may withhold notice if the trustee determines in good faith that withholding notice is in the interests of the holders.

In addition, we are required, so long as any of the senior debt securities are outstanding, deliver to the trustee, within 120 days after the end of each fiscal year, an officer’s certificate stating whether or not, to the knowledge of the signers thereof, we are in default in the performance and observance of any of the terms, provisions and conditions of the indenture (without regard to any period of grace or requirement of notice provided hereunder), and if a default or event of default shall have occurred, specifying all such defaults or events of default and the nature and status thereof of which we may have knowledge. We also are required, so long as any of the senior debt securities are outstanding, to deliver to the trustee, within 30 days after becoming aware of any default or event of default, an officer’s certificate specifying such default or event of default and what action we are taking or propose to take with respect thereto.

We and the trustee may amend the indenture as to the senior debt securities of any series with the written consent of the holders of a majority in principal amount of the senior debt securities of such series

then outstanding. Any past default or compliance with any provisions of the indenture or the senior debt securities of such series may be waived with the written consent of the holders of a majority in principal amount of the senior debt securities of such series then outstanding. These consents may be obtained through a tender offer or exchange offer for the senior debt securities of such series.

reduce the amount of senior debt securities of such series whose holders must consent to an amendment, supplement or waiver;

reduce the rate of or extend the time for payment of interest (including default interest) on any debt security of such series;

reduce the principal of or premium, if any, on any debt security of such series or change its maturity, including the stated maturity or the date of redemption or required repurchase thereof;

reduce the principal amount of discount securities payable upon acceleration of the maturity thereof;

make any debt security of such series payable in any currency other than that stated in the debt security of such series;

impair the right of any holder of any debt security of such series to receive payment of principal of and interest on the senior debt securities of such series on or after the due dates for the payment of the principal or interest or to institute suit for the enforcement of any payment on or with respect to the senior debt securities of such series;

make any changes that would affect the ranking of the senior debt securities of such series in a manner adverse to the holders thereof;

make any change in the amendment or waiver provisions relating to the senior debt securities of such series that require the consent of each holder thereof; or

make any change in Sections 6.8 or 6.13 of the indenture relating to the right of holders to receive payment of principal and interest and the waiver past defaults.

cure, correct or supplement any ambiguity, omission, defect or inconsistency as to the senior debt securities of such series;

comply with Article V of the indenture, including the assumption by a successor entity of our obligations under the indenture as to the senior debt securities of such series;

provide for uncertificated senior debt securities in addition to or in place of certificated senior debt securities;

add guarantees or collateral security with respect to the senior debt securities of such series;

add to our covenants under the indenture for the benefit of the holders of the senior debt securities of such series or to surrender any right or power conferred upon us as to the senior debt securities of such series;

make any change that does not adversely affect the rights of any holder of senior debt securities of such series in any material respect;

provide for the issuance of and establish the form and terms and conditions of securities of any series as permitted by the indenture;

change or eliminate any of the provisions of the indenture provided that any such change or elimination will become effective only when there is no security outstanding of any series created prior to the execution of such amendment or supplement that is adversely affected by such provision;

evidence and provide for the acceptance of appointment hereunder by a successor trustee with respect to the securities of one or more series and to add to or change any of the provisions of this indenture as shall be necessary to provide for or facilitate the administration of the trusts hereunder by more than one trustee; or

comply with any requirement of the SEC regarding qualification of the indenture under the Trust Indenture Act of 1939.

Unless we indicate differently in any applicable prospectus supplement or free writing prospectus, the senior debt securities initially will be issued in book-entry form and represented by one or more global notes or global securities, or, collectively, global securities. The global securities will be deposited with, or on behalf of, The Depository Trust Company, New York, New York, as depositary, or DTC, and registered in the name of Cede & Co., the nominee of DTC. Unless and until it is exchanged for individual certificates evidencing securities under the limited circumstances described below, a global security may not be transferred except as a whole by the depositary to its nominee or by the nominee to the depositary, or by the depositary or its nominee to a successor depositary or to a nominee of the successor depositary.

a limited-purpose trust company organized under the New York Banking Law;

a “banking organization” within the meaning of the New York Banking Law;

a member of the Federal Reserve System;

a “clearing corporation” within the meaning of the New York Uniform Commercial Code; and

a “clearing agency” registered pursuant to the provisions of Section 17A of the Exchange Act.

DTC holds securities that its participants deposit with DTC. DTC also facilitates the settlement among its participants of securities transactions, such as transfers and pledges, in deposited securities through electronic computerized book-entry changes in participants’ accounts, thereby eliminating the need for physical movement of securities certificates. “Direct participants” in DTC include securities brokers and dealers, including underwriters, banks, trust companies, clearing corporations and other organizations. DTC is a wholly-owned subsidiary of The Depository Trust & Clearing Corporation, or DTCC. DTCC is the holding company for DTC, National Securities Clearing Corporation and Fixed Income Clearing Corporation, all of which are registered clearing agencies. DTCC is owned by the users of its regulated subsidiaries. Access to the DTC system is also available to others, which we sometimes refer to as indirect participants, that clear through or maintain a custodial relationship with a direct participant, either directly or indirectly. The rules applicable to DTC and its participants are on file with the SEC.

Purchases of securities under the DTC system must be made by or through direct participants, which will receive a credit for the securities on DTC’s records. The ownership interest of the actual purchaser of a security, which we sometimes refer to as a beneficial owner, is in turn recorded on the direct and indirect participants’ records. Beneficial owners of securities will not receive written confirmation from DTC of their purchases. However, beneficial owners are expected to receive written confirmations providing details of their transactions, as well as periodic statements of their holdings, from the direct or indirect participants through which they purchased securities. Transfers of ownership interests in global securities are to be accomplished by entries made on the books of participants acting on behalf of beneficial owners. Beneficial owners will not receive certificates representing their ownership interests in the global securities, except under the limited circumstances described below.

To facilitate subsequent transfers, all global securities deposited by direct participants with DTC will be registered in the name of DTC’s partnership nominee, Cede & Co., or such other name as may be requested by an authorized representative of DTC. The deposit of securities with DTC and their registration in the name of Cede & Co. or such other nominee will not change the beneficial ownership of the securities. DTC has no knowledge of the actual beneficial owners of the securities. DTC’s records reflect only the identity of the direct participants to whose accounts the securities are credited, which may or may not be the beneficial owners. The participants are responsible for keeping account of their holdings on behalf of their customers.

So long as the securities are in book-entry form, you will receive payments and may transfer securities only through the facilities of the depositary and its direct and indirect participants. We will maintain an office or agency in the location specified in the prospectus supplement for the applicable securities, where notices and demands in respect of the securities and the indenture may be delivered to us and where certificated securities may be surrendered for payment, registration of transfer or exchange.

DTC notifies us that it is unwilling or unable to continue as a depositary for the global security or securities representing such series of securities or if DTC ceases to be a clearing agency registered under the Exchange Act at a time when it is required to be registered and a successor depositary is not appointed within 90 days of the notification to us or of our becoming aware of DTC’s ceasing to be so registered, as the case may be;

we determine, in our sole discretion, not to have such securities represented by one or more global securities; or

an Event of Default has occurred and is continuing with respect to such series of securities,