Bolt-Hole Caster, 3/8 in Bolt Hole Dia., 3/8 in Mounting Bolt Dia., Steel Caster Frame Material, Zinc Plated Frame Finish, 0 to 299 lb Load Rating Range, 220 lb Load Rating, 2 Number of Wheels, Ball, 3 7/8 in Mounting Height, 3 in Wheel Dia., 1 in Wheel Width, Rubber Wheel/Tread Material, 85 Shore A Wheel/Tread Hardness, Soft, Yes Non-Marking