Features: Lens collar support is specially designed for RF 100-500mm F4.5-7.1L IS USM lens. Great replacement for the original RF 100-500mm F4.5-7.1L tripod mount base USM lens. Made of high-quality aluminum alloy material, using anodizing, precision CNC machining, lightweight hollow design, vibration polishing technology, improve the hardness and uniformity of the metal surface by 20%, durable. Inner wall of the tripod ring bracket is irregular in structure and fits perfectly with the lens, plastic film ensures that the surface of the lens will not be worn, plate length is about 55mm, built-in camera quick release plate for tripod for head, equipped with 1/4" and 3/8" screw holes. Bottom is standard RRS interface quick release plate, for RRS / KIRK / WIMBERLEY / MARKINS / SUNWAYFOTO / KANGRINPOCHE / BENRO / SIRUI / MARSACE ballhead. Specifications: Material: Aluminum Alloy Color: Black Plate Length: about 55mm/2.16", with 1/4" and 3/8" screw holes Applicable Model: for RF 100-500mm F4.5-7.1L IS USM Lens Note: 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 Lens Tripod Mount Ring Base