Widely compatible with most Garmin tail light rearview radar models, including Varia RTL510, Varia RTL515, Varia RVR315, and Varia RTL500. Also compatible with Magene L508 Bike Radar Tail Light. The mounting bracket is constructed from high-quality aluminum alloy, providing a solid and durable attachment to your bicycle. It securely mounts under the saddle, ensuring stable installation and preventing loss of the radar due to loose fitting on the seat post. This mount positions the radar in a higher location under the saddle compared to seat post mounting, enhancing detection of approaching vehicles. It supports improved visibility and audible alerts for better awareness and safer riding. Quick and easy to install with included screws and a bonus metric Allen wrench. The design attaches securely to saddle rails and remains stable even on uneven terrain. Please measure your saddle before installation. The distance between the two mounting points on the saddle must be within 53–58 mm.