EXHIBIT 4.2

LOCKUP AGREEMENT

THIS LOCKUP AGREEMENT(this "Agreement"), made and entered into effective the 1st day of January, 2001, by and
amongRUSSELL J. CRECRAFT("RJC"),GREG M. HAUGEN("GMH"),JOHN I.
HESS("JIH"),THOMAS A. LODER("TAL"), andDAH WEN TSANG("DWT")
(together the "Withdrawing Members"),PATRICK P.H. SIRETA("PPS") andSIRETA, L.L.C.("Sireta")
(together the "Remaining Members").

RECITALS:

WHEREAS, the Withdrawing Members and the Remaining Members currently constitute all of the members of
Tremoliere, L.L.C. (the "Company");

WHEREAS, immediately prior to the execution of this Agreement, the Withdrawing Members delivered a joint notice to the Company
expressing their desire to withdraw immediately from the Company;

WHEREAS, in the event of such a withdrawal, each of the Withdrawing Members will be entitled to receive, in exchange for such
Withdrawing Member's interest in the Company, 375,000 shares of the common stock of Advanced Power Technology, Inc. ("APT") currently owned by the Company;

WHEREAS, the Remaining Members are willing to waive the six month notice period required in connection with a withdrawal from the
Company and allow the Withdrawing Members to withdraw immediately, provided that the Withdrawing Members enter into this Agreement; and

WHEREAS,the Withdrawing Members desire to enter into this Agreement to so satisfy the Remaining Members' desire and thereby allow for
such withdrawal;

NOW, THEREFORE, in consideration of the premises and the mutual promises and agreements contained herein, the parties hereto, intending
to be legally bound, hereby agree as follows:

Permission to Withdraw.The Remaining Members hereby agree to pass all such resolutions, sign all such documents and take all such further actions as
are necessary to (i) permit the Withdrawing Members to withdraw from the Company, effective immediately and (ii) cause the Company to distribute shares of common stock of APT to the
Withdrawing Members in the amount specified in the Recitals above.

2.Agreement Not to Transfer.Each Withdrawing Member and each Remaining Member
(each a "Member") does hereby agree, subject to Section 3 below, that for the period commencing on the date hereof and continuing through December 31, 2001 (the "Restriction Period"),
such Member shall not offer to sell, contract to sell, sell or otherwise dispose of any shares of common stock of APT owned by such Member, whether or not received as a result of such Member's
withdrawal from the Company, or any securities convertible into or exercisable or exchangeable for shares of common stock of APT without the prior written consent of all other Members.

3.Limitations on Restriction of Transfer.The restrictions on transfer set
forth in Section 2 shall not (i) prohibit any Member from selling shares of APT common stock during the Restriction Period as part of a secondary public offering of shares by APT or
(ii) prohibit any Member from transferring shares of APT common stock to the extent that such transfer would constitute a completed gift of such shares under the Internal Revenue Code of 1986,
as amended.

4.Miscellaneous.



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IN WITNESS WHEREOF,the parties have executed this Agreement effective the day and year first above written.

|                           |  |                      
|-------------------------- |  | ---------------------
|"Remaining Members"        |  | "Withdrawing Members"
|SIRETA, L.L.C.             |  | RUSSELL J. CRECRAFT  
|By:Patrick Sireta, Manager |  |                      
|                           |  | GREG M. HAUGEN       
|PATRICK SIRETA             |  |                      
|                           |  | JOHN I. HESS         
|                           |  | THOMAS A. LODER      
|                           |  | DAH WEN TSANG        

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