Hey jim-
The shim is a small piece that is installed using a tacy glue strip that self seals to the grip for a positive grab. Once installed properly there is no way that thing can come out of there. There is no modification to the firearm, and in easily user installed. If you have any further questions feel free to give me call. (800)442-2406
Take care,
Nate L
Thanks Nate,
I called but was told you were at at lunch so I'll ask this question here. If this Laser ever needs to be sent back to Crimson Trace for repairs can it be removed from the pistol with this adhesive holding it on? Thanks again! Jim...