1Compatibility: Specifically designed for T70180F2.8 first generation lens, this tripod mount ring greatly facilitates balance on a tripod and securely fastens heavy lenses, transferring weight away from the camera body. 2AS Standard: This lens collar features a 70mm quick mounting plate with 1/4in and 3/8in screw holes and for Arca compatible interface, which can be used with a tripod ball head, panoramic ball head, and clamp for optimal compatibility. 3Fine Craftsmanship: This ring is made of aluminum alloy, and features CNC machining, weight reduction through hollowing, polishing, anodizing on the surface, and an anti skid sticker on the inside to protect your lens from scratches. 4Versatility: The ring can be mounted on a tripod to provide stable support and balance for heavy telephoto lenses or those extending far from the camera front. Weighing approximately 144 grams, it has an internal diameter of about 80mm. 5Quick and Easy Installation: With designations on the tripod ring corresponding to those on the lens, simply align the dots and rotate the lens for secure attachment. By adding a collar to your lens you can achieve better balancing on a tripod. 1 xTripod Mount Ring 1 x Wrench