Katu Large Office Chair Casters Wheels for Hardwood - Heavy Duty Replacement for Laminate and Carpets. (Set of 5) Color Black & Dark Gray SAFE FOR HARDWOOD FLOORS, Office chair casters safe for all floors, hardwood, laminate and more. STANDARD SIZE, This chair caster come with the standard 7/16" (11mm) stem and polyurethane wheels. HEAVY DUTY, Set of 5 supports 550 lbs making it the best replacement for your desk or office chair. 5 YEARS WARRANTY, Eliminates the need of office floor mats. Install in minutes with no tools. SMOOTH MOVEMENTS, 65mm (2 9/16") diameter wheels lubricated with Lithium grease for smooth movement with a layer of rubber PU.