1 piano caster/wheel. Typically found on US made spinets and consoles in the back corners. New. Includes socket, bushing & 3 thicknesses of shims (may or may not be required but midway through the job isn't the time to find out you needed them) and screws. 2 1/8" diameter mounting socket, mounts in approx 5/8" hole (probably what's there already). 1 3/8" diameter wheel, 1" wide.