JJC TR-1 tripod mount ring is a high quality replacement for the Canon original A-2 Tripod Mount Ring. By adding a tripod collar to your lens you can achieve a better balance when mounted on a tripod. Rotating the camera is also much easier and faster when using a tripod ring. This tripod mount ring is designed to replace the manufacturer branded version. It will only work on the exact lens or lenses shown in the product title.