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 Compatible with Garmin Edge 820, 520, 510, 500, 25, and 20 Replaceable Garmin insert with K-EDGE "Definitive Click" locking system Carbon bar safe. Fits 31.8 mm bars Weight: 48g 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 builds on that 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 quickly and easily installs and secures on any bike in your stable, eliminating the need for multiple Varia mounts or dealing with slower bolt-on Varia mounts Safe The ATOP lacing system and rubber adapter pad provide a soft interface that won't scratch or wear your carbon or aluminum seatpost Secure Ride confidently knowing your Garmin Varia mount is securely dialed-in with the strong and dependable ATOP lacing system, without the fear of a failing single rubber band