V-Groove Track Wheel, 550 lb Load Rating, 300 to 999 lb, 8 in Wheel Dia., 3 in Wheel Width, Steel Wheel/Tread Material, Extra Hard Wheel/Tread Hardness Rating, 179 BHN Wheel/Tread Hardness, Tapered Roller Wheel Bearing Type, V-Groove Tread Shape, For Axle Size 3/4 in, 1 3/8 in Groove Width, Not Included Includes Spanner Bushing, Steel Wheel Core Material, Yes Non-Marking, 3 1/2 in Hub Length