1.Adopts AS Standard: The bottom of the lens collar is an 80mm/3.1in quick release plate with for Arca interface that is compatible with tripod ball heads, panoramic heads and for Arca interface clamps. 2.Compatible Lens: Designed for RF100500mm F4.57.1 L IS USM lens, it helps to better balance the camera and lens on a tripod, to better secure heavy lenses, and to take the weight of the lens off the camera body. 3.1/4in 3/8in Threaded Holes: The bottom of the lens tripod mount ring is pre drilled with 1/4in and 3/8in threaded holes, which can be mounted on a tripod to help you secure and balance heavy telephoto lenses or those hanging from the front of the camera. 4.Installation Advice: There is a plastic composite film that will not wear down the lens when properly installed. There should not be stickers on the lens mounting position, please remove them if there are any, otherwise it will affect the normal installation. It can be rotated like the original tripod ring after installation.