The Stem Cap Light Mount is a great way to mount a light, computer, power meter, or GPS unit right in the center of your handlebar and stem. Designed to replace the top cap of a threadless stem, this light mount provides a perch for accessories that would normally mount on the handlebars. This is especially useful if your bars are already crowded by grips, brake levers, and shifters. Like the traditional cap it replaces, the Stem Cap Light Mount comes with its own screw for headset adjustment. Fits 1 1/8" threadless steerer. Black anodized. 24g. 26.0 outside clamp diameter x 19mm wide.