What is a tripod mount ring? A tripod mount ring is a device that comes pre-equipped with some lenses. They are attached to the lens itself and allow the lens to be attached to a tripod. Why is this important? If the lens is much heavier than the camera body, the system is better balanced on the tripod. The tripod mount ring also allows the camera to be rotated vertically or horizontally without moving the tripod head.
Although tripod rings are very useful when you are using a tripod, it can add weight and instability if you are hand holding your camera. If you use your ring but occasionally find yourself hand holding your camera, turn the ring so that the tripod mounting side is up and not in the way. If you do not plan to use the ring for its intended purpose and are able to remove the ring, you might consider removing it as it adds unnecessary weight to your bag. Your back will be much happier.