The Canon Tripod Mount Ring is the tripod collar for the Canon EOS EF 70-300mm F4- 5.6L IS USM Lens. By adding a tripod collar to your lens you can achieve better balancing on a tripod. The tripod ring also makes a big difference in minimizing vibrations. In addition, rotating the camera will now be much easier and faster. The ring is very easy to put on and take off the lens as the lens does not need to be removed from the camera.