EXHIBIT 4



                                                                   May 10, 1995




General Signal Corporation
G.S. Newco Inc.
Stamford, CT

Gentlemen:

     This letter is being delivered to you in connection with, and to induce
you to enter into, the Agreement and Plan of Merger by and among General Signal
Corporation ("Parent"), G.S. Newco Inc. ("Merger Sub") and Best Power
Technology, Incorporated dated as of May 10, 1995 (the "Merger Agreement"), a
copy of which is attached hereto as Annex 1.

     You and the undersigned prior to the delivery hereof had no agreement,
arrangement or understanding to acquire the Shares (as defined hereinafter) or
for the purpose of acquiring, holding, voting or disposing of the Shares. 
Prior to the delivery hereof, the Board of Directors of Best Power Technology,
Incorporated, a Delaware corporation ("the Company"), has approved you and the
undersigned entering into this letter agreement and the transactions
contemplated by this letter agreement, as well as the execution and delivery by
the Company of the Merger Agreement providing for the merger of the Company
with a direct wholly-owned subsidiary of yours (the "Merger") and the offer to
purchase all outstanding shares of common stock, par value $.01 per share (the
"Company Common Stock"), of the Company (the "Offer").

     The undersigned hereby represents and warrants to, and covenants and
agrees with, Parent as follows:

     a.   Your and the undersigned's obligations hereunder shall be subject to
the condition that the Merger, the Offer and this letter agreement shall have
been approved by the Board of Directors of the Company with the effect that
Parent will not be subject to the restrictions of Section 203 of the Delaware
General Corporation Law.

     b.   The undersigned is the beneficial and/or record holder of 1,160,056
shares of Company Common Stock (the "Shares") and/or has the right to acquire 
no shares of Company Common Stock, free and clear of all liens and security 
interests whatsoever.

     c.   The undersigned will tender all of the Shares to Merger Sub pursuant
to the Offer, as the Offer may be amended by its terms or in accordance with
the Merger Agreement.  Such tender shall be made promptly after (but in no
event later than May 26, 1995) the






















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undersigned has received the Offer in the form of an Offer to Purchase.  The
undersigned further agrees not to withdraw such tendered Shares, unless the
Offer is extended beyond December 31, 1995 or unless the Merger Agreement is
terminated.

     d.   The undersigned will not, except pursuant to the Offer, assign, sell,
transfer or otherwise dispose of, including by way of pledge, hypothecation or
grant of any security interest, any of the Shares, or enter into any direct or
indirect agreement or arrangement to effect any of the foregoing, on or before
December 31, 1995 or, if earlier, the termination of the Merger Agreement or
the termination of the Offer in accordance with their respective terms,
provided, however, the undersigned may transfer Shares to a trust created by
the undersigned provided the trustee of the trust agrees to be bound by this
letter agreement to the same extent as the undersigned.

     e.   Subject to paragraph (f) below, the undersigned agrees that, prior to
the earlier of the Effective Time (as defined in the Merger Agreement), the
termination of the Merger Agreement in accordance with its terms and December
31, 1995, the undersigned shall not, directly or indirectly, solicit, initiate
or encourage (including by way of furnishing information) inquiries or
proposals concerning any Acquisition Transaction (as defined in the Merger
Agreement) or negotiate, explore or otherwise communicate with any third party
(other than Parent or its affiliates) regarding any Acquisition Transaction.

     f.   Parent and Merger Sub each acknowledge that the undersigned has
entered into this letter agreement solely in his/her capacity as a stockholder
of the Company and that by entering into this letter agreement the undersigned
has not limited in any way his/her ability to discharge or perform his/her
fiduciary duty, to the extent applicable, as a director of the Company and
subject to the terms and conditions of the Merger Agreement.

     g.   If Parent, Merger Sub or any subsidiary of Parent purchases the
Shares pursuant to the Offer and does not acquire a majority of the outstanding
shares of Company Common Stock pursuant to the Offer, Parent will pay promptly
to the undersigned in immediately available funds, in the event that it,
directly or indirectly, disposes of the Shares within 12 months of the date of
this letter agreement, any amount realized on such disposition of the Shares in
excess of the amount previously paid to the undersigned pursuant to the Offer.

     This letter agreement shall be governed by the laws of the State of
Delaware applicable to contracts made and performed wholly in such state.

                              Very truly yours,

                              /s/ Steve J. Paul





























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Agreed to:

GENERAL SIGNAL CORPORATION


By: /s/ Philip A. Goodrich
    -------------------------
     Name: Philip A. Goodrich
     Title: Vice President -
              Corporate Development

G. S. NEWCO INC.


By: /s/ Edgar J. Smith, Jr.
    -------------------------
     Name: Edgar J. Smith, Jr.
     Title: Vice President


Approved:

BEST POWER TECHNOLOGY, INCORPORATED


By: /s/ Dennis E. Burke
    -------------------------
     Name: Dennis E. Burke 
     Title: Executive Vice President -
              Administration

















































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