The Kupo KC-100S 100mm Castor Wheel With Square Adapter For Various Kupo Stands (3 pcs) is a set of 3 steel and rubber 3.0-15/16 inch (100mm) casters which fit 1" (25.4mm) square legs.. They feature an integral braking system that prevents rolling can be actuated with a tap of the foot. This set of casters has brakes that prevent the wheels from rolling and keeps your stand locked in place. Compatible with Kupo light stands and booms 546M , 310M and 543M