Features: Lens collar support is specially designed for RF 100-400mm f/5.6-8 IS USM lens. Inner wall of the tripod ring is irregular in structure, and the switch hole is reserved, which does not affect the use of the switch on the lens, the tripod ring cannot be rotated, and only supports horizontal shooting. Made of aviation aluminum material, precision CNC machining, lightweight hollow design, polished and anodized finish on the surface, exquisite workmanship and durable for long service life. Plate length is about 50mm, built-in Arca standard quick release plate for tripod for head, equipped with 1/4" and 3/8" screw holes, and stainless-steel anti-slip screws, allows you to fix the lens to the tripod directly. Bottom is 39mm Arca-Swiss standard dovetail groove quick release plate, for RRS / ARCA-SWISS tripod for head clamp of Arca 39mm fit, suitable for IS-JZ30, IS-JZ50, IS-JZ64, IS-QJ58 and more. Specifications: Material: Aluminum Alloy Color: Black Lens Inner Diameter: about 76mm/2.99", width: about 22mm/0.87" Plate Length: about 50mm/1.97", with 1/4" and 3/8" screw holes Applicable Model: for RF 100-500mm 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, which will not wear the lens surface when installed correctly; there should be no stickers on the lens surface installation position, if any, tear it off, otherwise it will affect the normal installation. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1 Piece IS-RF140 Lens Tripod Mount Ring