Large Heavy Duty Office Chair Casters 3" Nylon Twin Wheel - Ideal for Carpet Set of 5 Nylon wheels - Ideal for carpet and floor mats Heavy Duty support - 165 pound capacity per caster Large size 3" (75mm) - 3-1/4" Mounting Height High quality replacement for factory casters Grip ring stem size: 7/16" diameter; 7/8" length