V-Groove Track Wheel, 800 lb Load Rating, 300 to 999 lb, 4 in Wheel Dia., 1 1/2 in Wheel Width, Iron Wheel/Tread Material, Extra Hard Wheel/Tread Hardness Rating, Roller Wheel Bearing Type, V-Groove Tread Shape, For Axle Size 1/2 in, Included Includes Spanner Bushing, Iron Wheel Core Material, Yes Non-Marking, 1 7/8 in Hub Length