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