This is the Garmin Quarter-turn to Friction Flange Mount Adapter. It attaches the Garmin Varia UT800 smart headlight to the out front mounts for Garmin Edge cycling computers. Alternatively, hack-it to quickly attach or remove accessories that use a GoPro-Style mount to the your out-front mount. Compatible only with Garmin Out-Front Mounts. Note: Compatible with the Garmin Varia UT800 Smart Headlight Includes: Mount Hex screw Wrench