SC TO-T/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE TO

(Amendment No. 6)

TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)

OF THE SECURITIES EXCHANGE ACT OF 1934

ZOLL MEDICAL CORPORATION

(Name of Subject Company (Issuer))

ASAHI KASEI CORPORATION

ASCLEPIUS SUBSIDIARY CORPORATION

(Name of Filing Persons (Offerors))

Common Stock, $0.01 Par Value Per Share

(Title of Class of Securities)

989922109

(CUSIP Number of Class of Securities)

Takashi Shimodaira

General Manager, 1st Group, Legal Dept.

Asahi Kasei Corporation

1-105 Kanda Jinbocho, Chiyoda-ku

Tokyo, Japan, 101-8101

+81 3 3296 3009

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications on Behalf of Filing Persons)

Copies to:

Christopher E. Austin

John Palenberg

Cleary Gottlieb Steen & Hamilton LLP

One Liberty Plaza

New York, New York 10006

(212) 225-2000

CALCULATION OF FILING FEE

Transaction Valuation*	Amount of Filing Fee**
$ 2,259,915,810	$258,987

* Estimated solely for purposes of calculating the filing fee pursuant to Rule 0-11(d) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). The Transaction Valuation was calculated on the basis of (a) 24,300,170 shares of common stock, $0.01 par value per share, of ZOLL Medical Corporation (the “Shares”), the estimated maximum number of Shares that may be acquired in this tender offer (consisting of, as of March 9, 2012, (i) 22,277,142 Shares issued and outstanding (including 162,318 Shares in respect of outstanding restricted stock awards) and (ii) 2,023,028 Shares issuable upon the exercise of outstanding options) multiplied by (b) the offer price of $93.00 per Share.

** The filing fee was calculated in accordance with Rule 0-11 under the Exchange Act and Fee Rate Advisory #3 for fiscal year 2012, issued September 29, 2011, by multiplying the transaction value by 0.0001146.

x Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid:	$258,987	Filing Party:	Asahi Kasei Corporation, Asclepius Subsidiary Corporation
Form or Registration No.:	Schedule TO-T	Date Filed:	March 26, 2012

¨ Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the statement relates:

x third-party tender offer subject to Rule 14d-1.

¨ issuer tender offer subject to Rule 13e-4.

¨ going-private transaction subject to Rule 13e-3.

¨ amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results of the tender offer: ¨

This Amendment No. 6 amends and supplements the Tender Offer Statement on Schedule TO (as amended and supplemented, the “Schedule TO”), originally filed with the SEC on March 26, 2012 by Asclepius Subsidiary Corporation, a Massachusetts corporation (“Purchaser”) and an indirect wholly-owned subsidiary of Asahi Kasei Corporation, a corporation organized in Japan (“Asahi Kasei”), to purchase all outstanding shares of common stock, par value $0.01 (the “Shares”), of ZOLL Medical Corporation, a Massachusetts corporation (“ZOLL”), at a price of $93.00 per Share, net to the seller in cash, without interest thereon and less any required withholding taxes, upon the terms and subject to the conditions set forth in the Offer to Purchase dated March 26, 2012 (the “Offer to Purchase”), which is annexed to and filed with the Schedule TO as Exhibit (a)(1)(A), and in the related Letter of Transmittal, which is annexed to and filed with the Schedule TO as Exhibit (a)(1)(B), which, together with any amendments or supplements thereto, collectively constitute the “Offer.” All capitalized terms used in this Amendment No. 6 without definition have the meanings ascribed to them in the Schedule TO.

Items 1-11.

Items 1-11 of the Schedule TO are hereby amended and supplemented as follows:

The Offer to Purchase is hereby amended and supplemented by including the following:

“Asahi Kasei has issued a press release announcing that the subsequent offering period expired at 12:00 Midnight, New York City time, at the end of April 25, 2012. The depositary for the Offer has advised Asahi Kasei and Purchaser that, as of such time, combined with the shares tendered in the initial offering period, a total of 20,745,382 outstanding Shares were tendered, representing approximately 93.05% of the outstanding Shares. Purchaser has accepted for payment all Shares that were validly tendered and not properly withdrawn, and payment for such Shares will be made promptly.

Purchaser intends to effect a short-form merger pursuant to Section 11.05 of the Massachusetts Business Corporation Act without the need for a meeting of the ZOLL shareholders. In the Merger, each issued and outstanding share of ZOLL, other than shares held by ZOLL, Asahi Kasei or Purchaser, or any of their respective subsidiaries, and shares held by shareholders who properly exercise appraisal rights, if any, available under Massachusetts law, will be canceled and converted into the right to receive the same cash price per share as in the Offer, without interest thereon and less any required withholding taxes.

Upon completion of the merger, ZOLL will become a wholly owned subsidiary within the Asahi Kasei Group, managed by the current ZOLL management team and with all current business units and operations remaining intact. ZOLL will be delisted from the NASDAQ Global Select Market following the Merger.

The full text of the press releases issued by Asahi Kasei on April 26, 2012 in connection with the expiration of the subsequent offering period is filed as Exhibit (a)(5)(H) and (a)(5)(I) hereto and is incorporated herein by reference.”

Item 12. Exhibits.

Item 12 of the Schedule TO is hereby amended and supplemented by inserting the following exhibits:

Exhibit (a)(5)(H)	Press Release regarding expiration of the tender offer issued by Asahi Kasei, dated April 26, 2012
Exhibit (a)(5)(I)	English translation of Japanese Press Release issued by Asahi Kasei, dated April 26, 2012

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SIGNATURE

After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this Schedule TO is true, complete and correct.

Dated: April 26, 2012

ASAHI KASEI CORPORATION
By:	/s/ Taketsugu Fujiwara
	Name: Mr. Taketsugu Fujiwara
	Title: President and Representative Director
ASCLEPIUS SUBSIDIARY CORPORATION
By:	/s/ Hideo Hikami
	Name: Mr. Hideo Hikami
	Title: President

EXHIBIT INDEX

Exhibit No.	Description
(a)(1)(A)	Offer to Purchase, dated March 26, 2012 (1)
(a)(1)(B)	Form of Letter of Transmittal (including Form W-9) (2)
(a)(1)(C)	Form of Notice of Guaranteed Delivery (3)
(a)(1)(D)	Form of Letter to Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees (4)
(a)(1)(E)	Form of Letter to Clients for Use by Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees (5)
(a)(5)(A)	Joint Press Release issued by Asahi Kasei and ZOLL, dated March 12, 2012 (6)
(a)(5)(B)	English Translation of Japanese Press Release issued by Asahi Kasei, dated March 12, 2012 (7)
(a)(5)(C)	Materials for Asahi Kasei Investor Presentation, dated March 12, 2012 (8)
(a)(5)(D)	Form of summary advertisement, published March 26, 2012 in The Wall Street Journal (9)
(a)(5)(E)	Press Release regarding commencement of the tender offer issued by Asahi Kasei, dated March 26, 2012 (10)
(a)(5)(F)	Press Release regarding expiration of the tender offer issued by Asahi Kasei, dated April 23, 2012 (11)
(a)(5)(G)	English translation of Japanese Press Release issued by Asahi Kasei, dated April 23, 2012 (12)
(a)(5)(H)	Press Release regarding expiration of the subsequent offering period issued by Asahi Kasei, dated April 26, 2012
(a)(5)(I)	English translation of Japanese Press Release issued by Asahi Kasei, dated April 26, 2012
(b)(1)	Commitment Letter, dated March 12, 2012, by and among UBS AG, Tokyo Branch and Asahi Kasei Corporation (13)
(b)(2)	English Language Summary of Debt Financing Agreement, dated April 9, 2012, by and among Asahi Kasei Corporation, UBS AG, Tokyo Branch, Sumitomo Mitsui Banking Corporation and certain lenders party thereto (14)
(c)	Not applicable
(d)(1)	Agreement and Plan of Merger, dated as of March 12, 2012, by and among Asahi Kasei, Asahi Kasei Holdings US, Inc., Purchaser and ZOLL (15)
(d)(2)	Confidentiality Agreement, effective as of January 25, 2012, by and between Asahi Kasei and ZOLL (16)
(d)(3)	Tender and Voting Agreement, dated as of March 12, 2012, by and among Asahi Kasei, Asahi Kasei Holdings US, Inc., Purchaser and certain shareholders of ZOLL (17)
(d)(4)	Limited Waiver of Tender and Voting Agreement, dated as of March 29, 2012, by Asahi Kasei, Asahi Kasei Holdings US, Inc. and Purchaser (18)
(e)	Not applicable
(f)	Not applicable
(g)	Not applicable
(h)	Not applicable

4

(1) Incorporated by reference to Exhibit (a)(1)(A) to the Schedule TO-T filed by Asahi Kasei on March 26, 2012

(2) Incorporated by reference to Exhibit (a)(1)(B) to the Schedule TO-T filed by Asahi Kasei on March 26, 2012

(3) Incorporated by reference to Exhibit (a)(1)(C) to the Schedule TO-T filed by Asahi Kasei on March 26, 2012

(4) Incorporated by reference to Exhibit (a)(1)(D) to the Schedule TO-T filed by Asahi Kasei on March 26, 2012

(5) Incorporated by reference to Exhibit (a)(1)(E) to the Schedule TO-T filed by Asahi Kasei on March 26, 2012

(6) Incorporated by reference to Exhibit 99.1 to the Schedule TO-C filed by Asahi Kasei on March 12, 2012

(7) Incorporated by reference to Exhibit 99.2 to the Schedule TO-C filed by Asahi Kasei on March 12, 2012

(8) Incorporated by reference to Exhibit 99.3 to the Schedule TO-C filed by Asahi Kasei on March 12, 2012

(9) Incorporated by reference to Exhibit (a)(5)(D) to the Schedule TO-T filed by Asahi Kasei on March 26, 2012

(10) Incorporated by reference to Exhibit (a)(5)(E) to the Schedule TO-T filed by Asahi Kasei on March 26, 2012

(11) Incorporated by reference to Exhibit (a)(5)(F) to the Schedule TO-T/A filed by Asahi Kasei on April 23, 2012

(12) Incorporated by reference to Exhibit (a)(5)(G) to the Schedule TO-T/A filed by Asahi Kasei on April 23, 2012

(13) Incorporated by reference to Exhibit (b)(1) to the Schedule TO-T filed by Asahi Kasei on March 26, 2012

(14) Incorporated by reference to Exhibit (b)(2) to the Schedule TO-T filed by Asahi Kasei on March 26, 2012

(15) Incorporated by reference to Exhibit 2.1 to the Form 8-K filed by ZOLL on March 12, 2012

(16) Incorporated by reference to Exhibit (d)(2) to the Schedule TO-T filed by Asahi Kasei on March 26, 2012

(17) Incorporated by reference to Exhibit 2.2 to the Form 8-K filed by ZOLL on March 12, 2012

(18) Incorporated by reference to Exhibit (d)(5) to the Schedule TO-T/A filed by Asahi Kasei on April 2, 2012

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EX-99.(A)(5)(H)

Exhibit (a)(5)(H)

NEWS RELEASE

Asahi Kasei Completes Subsequent Offering Period for ZOLL

Tokyo, Japan/ New York, NY, U.S. – April 26, 2012 – Asahi Kasei Corporation (TSE1: 3407, hereinafter: Asahi Kasei), Japan’s leading diversified chemical manufacturer with businesses in the health care, chemicals & fibers, homes & construction materials, and electronics sectors, announced today the completion of the subsequent offering period offered by its indirect wholly owned U.S. subsidiary Asclepius Subsidiary Corporation (hereinafter: Purchaser) for the remaining shares of common stock of ZOLL Medical Corporation (NASDAQ GS: ZOLL, hereinafter: ZOLL) following a tender offer for all of the outstanding ZOLL shares for $93 per share, net to the seller in cash, without interest and less any required withholding taxes.

As of the expiration of the subsequent offering period at 12:00 Midnight, New York City time, at the end of April 25, 2012, combined with the shares tendered in the initial offering period, a total of 20,745,382 ZOLL’s shares were tendered, representing approximately 93.05% of ZOLL’s outstanding shares.

Purchaser intends to effect a short-form merger pursuant to Section 11.05 of the Massachusetts Business Corporation Act without the need for a meeting of the ZOLL shareholders. In the merger, each issued and outstanding share, other than shares held by ZOLL, Asahi Kasei or Purchaser, or any of their respective subsidiaries, and shares held by shareholders who properly exercise appraisal rights, if any, available under Massachusetts law, will be canceled and converted into the right to receive the same cash price per share as in the Offer, without interest and less any required withholding taxes.

Upon completion of the merger, ZOLL will become a wholly owned subsidiary within the Asahi Kasei Group, managed by the current ZOLL management team and with all current business units and operations remaining intact. ZOLL will be delisted from the NASDAQ Global Select Market following the merger.

-Ends-

INVESTOR CONTACTS

Information Agent, Georgeson:	+1-212-440-9800 (Banks and Brokers)
	+1-888-607-9107 (All Others, Toll Free)

MEDIA CONTACTS

Asahi Kasei Corporation:
Corporate Communications:	Tokyo	+81-3-3296-3008 (M. Nakamura)
Kreab Gavin Anderson:	Tokyo	+81-3-5404-0640 (M. Hattori, D. Stawinoga0)
	New York	+1-646-490-2767 (J. Goldman-Brown)

NOTES TO EDITORS

About Asahi Kasei Corporation

Asahi Kasei is Japan’s leading diversified chemical manufacturer with businesses in the health care, chemicals & fibers, homes & construction materials, and electronics sectors. The company’s growth strategy involves continuous transformation of its business portfolio through constant innovation in anticipation of emerging changes to market needs, and through this process Asahi Kasei has developed into a diversified solution provider. With more than 25,000 employees around the world, the company serves customers in more than 100 countries.

Within the health care field, the company is active in pharmaceuticals (including agents for dysuria, osteoporosis, disseminated intravascular coagulation, and herpes), medical devices (including artificial kidneys and therapeutic apheresis devices), and bioprocess products (including virus removal filters and bioprocess equipment).

For more information, visit www.asahi-kasei.co.jp/asahi/en/.

About ZOLL Medical Corporation

ZOLL Medical Corporation develops and markets medical devices and software solutions that help advance emergency care and save lives, while increasing clinical and operational efficiencies. With products for defibrillation and monitoring, circulation and CPR feedback, data management, fluid resuscitation, and therapeutic temperature management, ZOLL provides a comprehensive set of technologies that help clinicians, EMS and fire professionals, and lay rescuers treat victims needing resuscitation and critical care.

A three-time Forbes 100 Most Trustworthy Company, ZOLL was designated in 2011 as one of Forbes Top 100 Small Public Companies in America with annual revenues under $1 billion. ZOLL develops and manufactures its products in the United States, in California, Colorado, Illinois, Massachusetts, Pennsylvania, and Rhode Island. More than 400 direct sales and service representatives, 1,100 business partners, and 200 independent representatives serve our customers in over 140 countries around the globe.

For more information, visit www.zoll.com.

Page 2 of 3

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This press release contains certain statements that are “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, as amended. Asahi Kasei and ZOLL have identified some of these forward-looking statements with words like “believe,” “may,” “could,” “would,” “might,” “possible,” “will,” “should,” “expect,” “intend,” “plan,” “anticipate,” or “continue,” the negative of these words, other terms of similar meaning or the use of future dates. Forward-looking statements in this release include without limitation statements regarding Asahi Kasei’s operation of the ZOLL business following completion of the transaction, and statements regarding the future operation, direction and success of ZOLL’s business. Such statements are qualified by the inherent risks and uncertainties surrounding future expectations generally, and actual results could differ materially from those currently anticipated due to a number of risks and uncertainties. Risks and uncertainties that could cause results to differ from expectations include the effects of disruption caused by the transaction making it more difficult to maintain relationships with employees, customers, vendors and other business partners; other business effects, including the effects of industry, economic or political conditions outside of the control of Asahi Kasei or ZOLL; transaction costs; actual or contingent liabilities; and other risks and uncertainties discussed in ZOLL’s filings with the U.S. Securities and Exchange Commission, including the “Risk Factors” sections of ZOLL’s most recent annual report on Form 10-K and subsequent quarterly report on Form 10-Q, as well as the tender offer documents filed by Asahi Kasei and Asclepius Subsidiary Corporation, an indirect wholly owned subsidiary of Asahi Kasei, and the Solicitation/Recommendation Statement filed by ZOLL. Neither Asahi Kasei nor ZOLL undertakes any obligation to update any forward-looking statements as a result of new information, future developments or otherwise, except as expressly required by law. All forward looking statements in this announcement are qualified in their entirety by this cautionary statement.

Page 3 of 3

EX-99.(A)(5)(I)

Exhibit (a)(5)(I)

News Release

April 26, 2012

Completion of the subsequent offering period to acquire ZOLL Medical Corporation

Asahi Kasei Corp. (headquarters: Chiyoda Ward, Tokyo; President: Taketsugu Fujiwara) completed the Subsequent Offering Period¹ (from April 23, 2012, to 24:00 on April 25, 2012, US Eastern time) through a US subsidiary (hereinafter: SPC) for shareholders of ZOLL Medical Corp. (headquarters: Massachusetts, USA; CEO: Richard A. Packer), a US manufacturer of critical care devices, who did not tender their shares during a tender offer (from March 26, 2012, to 24:00 on April 20, 2012, US Eastern time) for all of the outstanding common shares of ZOLL Medical for US$93 per share (hereinafter: Tender Offer).

As of the expiration of the Subsequent Offering Period at 24:00 on April 25, 2012, US Eastern time, 20,745,382 common shares of ZOLL Medical were tendered, representing approximately 93.05% of the total number outstanding shares, including shares tendered during the initial tender offer period.

On April 26, 2012 (US Eastern time), in accordance with relevant provisions of the Massachusetts Business Corporation Act, SPC plans to implement a Short Form Merger (a merger procedure that does not require a general meeting of shareholders), with ZOLL Medical as the surviving company. As part of this process, shares of ZOLL Medical that were not tendered in the Tender Offer (with the exception of those held by ZOLL Medical, Asahi Kasei, SPC, or any other direct or indirect subsidiary thereof, and those held by shareholders who exercise appraisal rights under Massachusetts law) will be cancelled and converted into the right to receive US$93 per share in cash, the same amount as the purchase price in the Tender Offer.

As a result of this merger, ZOLL Medical’s stock will cease to be traded on the NASDAQ market and ZOLL Medical will no longer have reporting obligations under the Securities Exchange Act of 1934. After the merger, ZOLL Medical will be a wholly owned consolidated subsidiary of Asahi Kasei, and will continue to be managed by ZOLL Medical’s current management team.

¹  Subsequent Offering Period: This is a system to establish an extra period that provides shareholders who did not tender their shares before the end of the initial tender offer period another opportunity to do so after the end of the initial tender offer period.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This press release contains certain statements that are “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, as amended. Asahi Kasei and ZOLL have identified some of these forward-looking statements with words like “believe,” “may,” “could,” “would,” “might,” “possible,” “will,” “should,” “expect,” “intend,” “plan,” “anticipate,” or “continue,” the negative of these words, other terms of similar meaning or the use of future dates. Forward-looking statements in this release include without limitation statements regarding Asahi Kasei’s operation of the ZOLL business following completion of the transaction, and statements regarding the future operation, direction and success of ZOLL’s business. Such statements are qualified by the inherent risks and uncertainties surrounding future expectations generally, and actual results could differ materially from those currently anticipated due to a number of risks and uncertainties. Risks and uncertainties that could cause results to differ from expectations include: 1) the effects of disruption caused by the transaction making it more difficult to maintain relationships with employees, customers, vendors and other business partners; 2) other business effects, including the effects of industry, economic or political conditions outside of the control of Asahi Kasei or ZOLL; 3) transaction costs; 4) actual or contingent liabilities; and 5) other risks and uncertainties discussed in ZOLL’s filings with the U.S. Securities and Exchange Commission, including the “Risk Factors” sections of ZOLL’s most recent annual report on Form 10-K and subsequent quarterly report on Form 10-Q, as well as the tender offer documents filed by Asahi Kasei and Asclepius Subsidiary Corporation, an indirect wholly owned subsidiary of Asahi Kasei, and the Solicitation/Recommendation Statement filed by ZOLL. Neither Asahi Kasei nor ZOLL undertakes any obligation to update any forward-looking statements as a result of new information, future developments or otherwise, except as expressly required by law. All forward looking statements in this announcement are qualified in their entirety by this cautionary statement.

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