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EXHIBIT 4 Cooper Industries, LLC Cooper Industries, Ltd. and JPMorgan Chase Bank as Trustee FOURTH SUPPLEMENTAL INDENTURE Dated as of January 1, 2005 DEBENTURES Supplement to Indenture dated as of January 15, 1990
As Amended by the
First Supplemental Indenture dated as of May 15, 2002, and the
Second Supplemental Indenture dated as of June 21, 2002, and the
Third Supplemental Indenture dated as of October 28, 2002




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This FOURTH SUPPLEMENTAL INDENTURE, dated as of January 1, 2005 (Supplemental Indenture), is
made and entered into between Cooper Industries, LLC, a Delaware limited liability company, having
its principal office at 600 Travis, Suite 5800, Houston, Texas 77002, Cooper Industries, Ltd., a
Bermuda company, having its principal office at 600 Travis, Suite 5800, Houston, Texas 77002 (the
Guarantor) and JPMorgan Chase Bank, a New York banking corporation, as Trustee (the Trustee). WHEREAS, Cooper Industries, LLC is a wholly owned, indirect subsidiary and a Restricted Subsidiary
of the Guarantor; and WHEREAS, Cooper Industries, Inc. merged with and into Cooper Industries, LLC effective January 1,
2005; and WHEREAS, Cooper Industries, Inc. entered into an Indenture dated as of January 15, 1990 (the
Indenture), with The Chase Manhattan Bank (National Association), for the purpose of issuing its
debentures, notes, bonds or other evidences of indebtedness (the Debentures) in one or more
series, unlimited as to aggregate principal amount and bearing such rates of interest, if any,
maturing at such time or times and having such other designations as shall be fixed in accordance
with the Indenture; and WHEREAS, pursuant to the First Supplemental Indenture among Cooper Industries, Inc., the Guarantor
and the Trustee dated as of May 15, 2002, the Guarantor has guaranteed to each holder of a
Debenture the payment of the principal of, premium, if any, and interest, if any, on the Debentures
and all other obligations of Cooper Industries, Inc. under the Indenture; and WHEREAS, the Trustee is the successor by merger to The Chase Manhattan Bank (National Association)
and has succeeded to all interests of such national association under the Indenture; and WHEREAS, Cooper Industries, Inc., the Guarantor and the Trustee entered into a Second Supplemental
Indenture dated as of June 21, 2002 and a Third Supplemental Indenture dated as of October 28,
2002; and WHEREAS, the entry into this Supplemental Indenture by the parties hereto is required by Article 12
of the Indenture and is in all respects permitted by the provisions of Section 11.01 of the
Indenture; and WHEREAS, all corporate and other action necessary to make this Supplemental Indenture a valid and
binding agreement of Cooper Industries, LLC and the Guarantor in accordance with its terms have
been done. 1




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NOW, THEREFORE, in consideration of the foregoing premises and the acceptance and purchase of the
Notes by the holders thereof, it is mutually covenanted and agreed as follows: Section 1.In accordance with Article 12 of the Indenture, Cooper Industries, LLC hereby
assumes the due and punctual payment of the principal of, premium, if any and interest, if any, on
all the Debentures and the performance or observance of every covenant of the Indenture on the part
of the Company to be performed or observed. Section 2.The Indenture is hereby amended by amending and restating in its entirety the
following definition in Section 1.01: Company: The term Company shall mean Cooper Industries, LLC, a Delaware limited liability
company, and subject to the provisions of Article Twelve, shall mean its successors and assigns. Section 3. The Indenture, as supplemented and amended by this Supplemental Indenture and
all other supplemental indentures thereto, is in all respects ratified and confirmed, and the
Indenture, the Supplemental Indenture and all indentures supplemental thereto shall be read, taken
and construed as one and the same instrument. Section 4. If and to the extent any provision hereof limits, qualifies or conflicts with
another provision hereof which is required to be included in this Supplemental Indenture by any
provision of the Trust Indenture Act of 1939, such required provision shall control. Section 5. In case any provision in this Supplemental Indenture or in the Debentures of
any series shall be invalid, illegal or unenforceable, the validity, legality and enforceability of
the remaining provisions (or of the other series of Debentures) shall not in any way be affected or
impaired thereby. Section 6. If the provisions of any subsequent series of the Debentures issued hereunder
are inconsistent or conflict with the provisions of this Supplemental Indenture, the provisions of
the Debentures of such series shall be controlling with respect to such series. Section 7. This Supplemental Indenture and each Debenture of any series shall be deemed to
be a contract made under the laws of the State of New York, and for all purposes shall be construed
in accordance with the laws of the said State. Section 8. Capitalized terms used in this Supplemental Indenture that are not otherwise
defined herein that are defined in the Indenture shall remain as set forth therein. 2




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Section 9. This Supplemental Indenture may be executed in any number of counterparts, each
of which shall be an original but such counterparts shall together constitute but one and the same
instrument. Section 10.The Trustee shall not be responsible in any manner whatsoever for or in respect
of the validity or sufficiency of this Supplemental Indenture or for or in respect of the recitals
contained herein, all of which are made solely by the Company and the Guarantor. IN WITNESS WHEREOF, the parties have caused this Fourth Supplemental Indenture to be duly executed
as of the day and year first above written. COMPANY:COOPER INDUSTRIES, LLC.
    
    JPMORGAN CHASE BANK,AS TRUSTEEBy:
/s/ Alan J. Hill
    
    By: /s/ Paul SchmalzelName: Alan J. Hill
    
    Name: Paul SchmalzelTitle: Vice President and Treasurer
    
    Title: Vice PresidentGUARANTOR:COOPER INDUSTRIES, LTD.By:
/s/ Terry A. KlebeName: Terry A. KlebeTitle: Senior Vice President and Chief Financial OfficerBy:
/s/ Alan J. HillName: Alan J. HillTitle: Vice President and Treasurer
 3