Caster Wheels Replacement,IWMH Office Chair Caster Soft Wheel Swivel Standard Size 11mm Stem 55mm Wheel Heavy Duty up to 550 lbs Max Capacity Wood Floor Chair Mat Protector Protection,Set of 5 Resistant Polyurethane Material - No more scratches on Hardwood floor, or any type of floor. Wheel Diameter: 2.5" (55mm) | Stem Diameter: 7/16" Grip Ring Type (11mm) | Stem Height: 0.86" (22mm) Maximum Weight Rating:100lbs-110lbs/wheel Lubricated with Lithium based grease for smooth movement Easy pull and snap installation  3 years Warranty