A method for lapping the gears of a gear set as well as a gear lapping system. An optical element is interposed between first and second semiconductor lasers. When a match is detected, the server computer writes a command in the update file for the client computer to copy an old segment of the client computer’s copy of the earlier version of the subscription file into the client computer’s copy of the current version of the subscription file, where the old segment corresponds to the segment for which a match was detected. The second isolation fluid is adapted for use in a first temperature range and couples a pressure from the second isolator diaphragm assembly to the second pressure outlet. The LCD panel and overhead projector may be provided an an integral unit. The second substrate is bonded to the one side of the first substrate where the channel opening 14b is formed so that the opening is blocked by the second substrate.