EXMAX Tripod Lens Collar Mount Ring with 1/4 Screw Mount for Canon EF 70-200mm f/4L, 300mm F4 USM and 400mm F5.6 USM Lens The tripod mount ring mount on the tripod, it helps you fix and balance your tele lens which is heavy or long lens hanging off the front of camera. It is sturdy and durable, and there is flocking at the junction to the lens, combination close without gaps. With 1/4 screw hole, convenient to be mounted on the tripod Surface hardening treatment, fine and smooth, wear-resistant Made by metal with very high quality