REVIVE YOUR DESK CHAIR: Replace or upgrade your office chair wheels with the replacement castor set from kwmobile. The caster wheel stems fit industry standard-sized 10mm sockets (check your chair before purchasing). CLICK AND GO: Easily swap and install your new office chair rollers in minutes. Simply slide the rod into the base and click into place. No special tools or hardware are needed. PROTECT YOUR FLOORS: These office chair casters have 20mm (0.79") long stems, and are designed for use on wood floors and other hard surfaces. Made of rubber to help prevent scratches and damage to your hardwood.