Tripod dolly is often used for shooting movies, when tracking shots are needed; usually those shots are carried out with a dolly mounted on rails. The Hypop dolly is a high quality camera tripod dolly. It has a 36 inch diameter and folds to only 21.5 inches for transport or storage. The heavy duty wheels feature ball bearings and quick foot operated locks. The leg locking clamps can be moved along the dolly arms to accommodate many different size tripods. It fits any tripod and comes with zippered nylon carrying bag.