GSI TR-1 Thumb Rotary Knob

The TR-1 replaces the thumb rotary knob on your GSI wheel with one machined from a solid block of 6061 aluminum, giving you smooth, precise rotation and a choice of blue, red or black anodizing.

Installation takes only a 1.5 mm hex bit: loosen (don’t remove) the grub screw on the existing knob, fit the TR-1 and tighten its pre-installed grub screw, stopping short of over-tightening. It fits the FPE V2, GXL V2 and Interlock.