Office Chair Caster Wheels for Hardwood - Laminate Floor Mat and all Floors (Set of 5) Black 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, lubricated with Lithium grease for smooth movement with a layer of rubber PU.