Photo Clam PQR ball heads feature a dual pan movement so you can rotate the camera from above the ball and rotate the set up at the base of the head. The also allows a level panning axis without having to level the tripod. The PQRS adds a lever release to quickly mount and remove the camera. Patented design fits any Arca-type plate. Built in bubble level. 77 lbs. max. load capacity. Weighs only .89 lbs.