1. The original structure and design of F (WIII) are adopted, and the function of quick release plate is added at the bottom; the inner wall of the tripod ring bracket is a concave-convex irregular structure, which is closely integrated with the lens; compatible with Canon RF 100-500mm f/4.5-7.1L IS USM Lens, can't be used for other lenses;.2. The contact surface is plastic composite film, will not wear lens surface when installed correctly; there should be no stickers on the lens surface installation position, if there is, remove it, otherwise it will affect the normal installation; after installation, it can be freely rotated like the original tripod ring;.3. The tripod collar bottom is added 60mm long Arca fit quick release plate feature, compatible with Arca-Swiss 39mm fit tripod ball head, panoramic head and clamp directly; more practical than lens collars without QR-Plate;.4. The Lens support bottom reserved 1/4" and 3/8" screw holes and stainless-steel anti-slip screws for fixing lens to tripod directly;.5. The lens collar IS-RF150 can be combined with clamp mount converter IS-3950PRO (Sold Separately), which can be used for hydraulic heads with Manfrotto structure.