Kibler Fowler Kit — Step 3: Installing the Thumbpiece

The thumbpiece should fit in its inlet with little to no further fitting. Lightly tapping it in place with a small mallet may help.

Secure the thumbpiece with the supplied machine screw, which is inserted below the trigger guard grip rail. It can be helpful to tap the thumbpiece lightly to seat it further in the inlet, then tighten the machine screw a small amount more.