AS Standard bottom with Arca quick release - The lens collar bottom uses an 80 mm / 3.1 in quick release plate with Arca interface, compatible with Arca clamps, tripod ball heads, and panoramic heads. Designed for RF100-500mm F4.5-7.1 L IS USM - Specifically engineered for the RF100-500mm F4.5-7.1 L IS USM lens to improve balance on a tripod, secure heavy lenses, and take weight off the camera body. 1/4 in and 3/8 in threaded holes - The bottom of the lens tripod mount ring is pre drilled with 1/4 in and 3/8 in threaded holes for tripod mounting to help secure and balance heavy telephoto lenses or those hanging from the front of the camera. Installation advice - Includes a plastic composite film that will not wear down the lens when properly installed. Do not have stickers on the lens mounting position; remove any if present, otherwise installation may be affected. After installation, it can rotate freely like the original tripod ring. Practical use scenarios - Field wildlife photography: Mount the RF100-500 on a stable tripod with the Arca plate to balance the rig and reduce strain on the camera body during long shoots. - Landscape and panoramic shooting: Use with Arca clamps and a compatible head to achieve smooth rotation and stable support for heavy telephoto lenses during sweeping scenes. - Front-facing and heavy-lens setups: Utilize the 1/4 in and 3/8 in threaded holes to secure the lens on a tripod, keeping the lens front-weighted setups stable and balanced.