• 1.The tripod ring is customized based on the shape and structure of the lens, only compatible with Canon RF 100-400mm f/5.6-8 IS USM lens, not compatible with other lenses. The inner wall of the tripod ring is uneven and the switch hole is reserved. This will not affect the use of lens switches. The tripod ring is not rotatable and only supports horizontal shooting • 2. The inner wall of the tripod ring and the lens contact surface is a plastic composite film, when properly installed will not wear the lens surface. You should not have a sticker on the lens surface to be mounted on. Peel off if applied Otherwise, it will affect normal installation • 3. The bottom of the lens bracket collar has a 50mm long Arca Fit quick release plate that can be used directly with the 39mm Arca Swiss Fit tripod ball head, panoramic head and clamp. More practical than lens support collars with no anticut • 4.On the bottom of the lens support collar there is 1/4" and 3/8" screw holes and stainless steel non-slip screws to secure the lens directly to the tripod • 5. Tripod socket IS-RF140 + IS-3950PRO quick release plate converter (sold separately) compatible with Manfrotto construction water head