Bike Computer Edge Mountain Varia Mount Tail Light Models ATOP Dial Security Varia Seatpost Under Saddle Mount Garmin Mount Dimensions: LxWxH 6 x 3 x 2 inches Compatible with the Edge 1000, Edge 1030, Edge 20, Edge 25, Edge 520, Edge 810, Edge 820, Edge Touring, and Edge Touring Plus. Ideal for off-road riding. Designed specifically for bikes with short stems. CONFIDENCE - While your Garmin Varia or similar radar system increases your awareness and personal security when you're out on the road, our Garmin Varia mount enhances confidence by providing a strong and secure mount for your Garmin Varia RTL510, Garmin Varia RTL515, or any other rear-facing device utilizing the Garmin quarter-turn system. NOTE: Not compatible with the Garmin Varia RCT715. ADAPTABLE - Utilizing the ATOP dial system, our Garmin Varia mount quickly and easily adapts with the turn of a dial to fit a variety of seatpost diameters and geometries: 27.2mm, 30.9mm, 31.6mm, D cross-section, or aero cross-section. QUICK CHANGE - The ATOP dial system allows for fast and secure installation on any bike, eliminating the need for multiple Varia mounts or slower bolt-on systems. SAFE - The ATOP lacing system and rubber adapter pad provide a soft interface that won't scratch or damage your carbon or aluminum seatpost. SECURE - Ride with confidence knowing your Garmin Varia mount is securely locked in place using the durable ATOP lacing system, without the risk of failure from a single rubber band.