Features: Lens collar support is specially made according to the lens's shape and structure and is only for RF 100-400mm f/5.6-8 IS USM lens. Made of aviation aluminum, CNC precision machining, hollow weight reduction design, polishing and surface anodizing, beautiful appearance and fine workmanship. The inner wall of the tripod ring with irregular irregular texture has reserved switch holes, which does not affect the use of the switch on the lens, it cannot be rotated and only supports horizontal shooting, not vertical shooting. A 50mm long Arca standard quick release plate is added to the bottom of the tripod ring, which can be directly matched with a 39mm Arca-swiss tripod ball for head, panorama gimbal, clamp, etc. 1/4" and 3/8" screw holes and stainless steel anti-slip screws are also reserved. , you can attach the lens directly to the tripod. The dovetail slot at the bottom of the lens mount is 39mm Arca-Swiss standard, for ISHOOT/RRS/ARCA-SWISS / tripod ball head for Arca 39mm, suitable for iShoot IS-JZ50/ IS-JZ64/IS-QJ58/IS- JZ60BK/IS-JZ70MFT/IS-JZ80BK etc. Specifications: Material: aluminum alloy Color: Black Lens inner diameter: approx. 76 mm/2.99" Width: Approx. 22 mm/0.87" Plate length: approx. 50 mm/1.97", with 1/4" and 3/8" screw holes Applicable model: for RF 100-500 mm F4.5-7.1L IS USM lens Note: The contact surface between the inner wall of the tripod ring and the lens is made of plastic composite film, and the lens surface will not be worn after being installed correctly; there should be no stickers on the lens surface. Please allow 0-1 cm error due to manual measurement. please make sure you don't mind before ordering. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Tripod Mount Ring IS-RF140