Exhibit 10.1
August 31, 2006
 
Len Foxman
Eagle Test Systems, Inc.
2700 Millbrook Drive
Buffalo Grove, IL 60089
Dear Len:
As you know, the Company is in the process of developing a compensation plan for
its executive team, including a review of salaries. To facilitate that process
you and we have agreed to extend your Employment Agreement which expires
September 30, 2006 (the “Agreement”) through December 31, 2006
Accordingly, the period for notice referred to in Section 2 of the Agreement
with respect to the period ending September 30, 2006 will be deemed timely given
if given at any time prior to December 1, 2006.
Please indicate your agreement by signing in the space indicated below.
Yours very truly,
Eagle Test Systems, Inc.

                By:   /s/ Michael Child         Michael Child, on behalf of the 
      Company and the Compensation Committee       

Agreed:
      /s/ Len Foxman
Len Foxman