Flat-Free Polyurethane Foam Wheel, 300 lb Load Rating, Smooth Tread, 9 5/16 in Wheel Dia., 1 3/4 in Wheel Width, For Axle Size 3/4 in, 9x3.50-4, Standard Tire Rim Type, Center Mount Hub Position, 4 in Hub Length, Steel Hub Material, Yes Non-Marking