Flat-Free Polyurethane Foam Wheel, 250 lb Load Rating, Sawtooth Tread, 6 1/8 in Wheel Dia., 1 7/8 in Wheel Width, For Axle Size 1/2 in, 6x2, Standard Tire Rim Type, Center Mount Hub Position, 2 3/8 in Hub Length, Steel Hub Material, Yes Non-Marking