Large Heavy Duty Office Chair Casters 3" (75mm) Softech Twin Wheel - Hardwood Floor Safe Wheels Set of 5 Thermoplastic elastomer rubber wheels - Safe for ALL floors, Non-marking and non-marring 3-3/16" Mounting Height Grip ring stem size: 7/16" diameter; 7/8" length High quality replacement for nylon casters Large size 3" (75mm) 165 pound capacity per caster