It dolly is made from aluminum with a radius of 20". It is light enough to be folded and carried around conveniently. Its universal leg locking device will fit almost any tripod. The most important feature of a good dolly is the good wheels. After all, the point of a dolly is to be able to smoothly move your tripod from one place to another. Unlike less expensive models with smaller plastic wheels, this dolly uses large 3" diameter wheels with all metal ball bearings and a rubber outer surface for an ultra smooth roll. Once you get the dolly where you want it, all you have to do is "step" on the locks for one or more of the wheels. It comes with a leg grip which slides along the dolly leg going either closer to the center or out to the end. This allows you to adjust the desired level of "spread" for the tripod you are using.