Stem Caster, Swivel Caster with Brake, 275 lb Load Rating, 0 to 299 lb, 4 in Wheel Dia., 1 1/4 in Wheel Width, Polypropylene Wheel/Tread Material, 5 in Mounting Height, Ball, 1/2 In. -13 Caster Stem Size, Threaded, Steel Caster Frame Material, Zinc Plated Frame Finish, Yes Non-Marking, 1 Number of Wheels