Rear SprocketCNC-machined from a specially enhanced 7075-T6 aluminum alloyMachined self-cleaning mud grooves at each tooth to help prevent mud buildup and increase wear resistanceUltralight design is 66% lighter than steel, yet incredibly durable#1 sprocket used in supercross, motocross and offroad throughout the worldProduct Name: Sprocket PITCH: 420 MATERIAL: Aluminum POSITION: Rear Units: Each TEETH: 50