If you own a canon 70 200 mm f4 l usm lens or a canon 70 200 mm f4 l is usm lens you own one of the best to make either of these lenses even better add a canon tripod mount ring a ii wthe canon tripod mount ring a ii w s main purpose is to provide a better balance when mounted on a tripod the 70 200 f4 lenses do not require this ring to be mounted on a tripod the camera body tripod insert can be used but this setup is front heavy a top notch ballhead can handle this load but