Office Chair Casters Wheels for Hardwood - Heavy Duty Replacement Parts, Protector for Laminate, Desk Floor Mats and Carpet. (Set of 5) Black & Gray SAFE FOR HARDWOOD FLOORS, Office chair casters safe for all floors, hardwood, laminate, vinyl flooring, floor mats and more. STANDARD SIZE, This chair caster come with the standard 7/16" (11mm) stem and polyurethane wheels to better protect your floors. 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, 2 3/8 inch wheels lubricated with Lithium grease for easy and smooth movement with a layer of rubber PU.