Flat-Free Polyurethane Foam Wheel, 675 lb Load Rating, Ribbed Tread, 15 1/2 in Wheel Dia., 3 1/2 in Wheel Width, For Axle Size 3/4 in, 4.80/4.00-8, Standard Tire Rim Type, Center Mount Hub Position, 3 in Hub Length, Steel Hub Material, Yes Non-Marking