This 68 tooth rear sprocket is made from hardened, corrosion resistant steel. Commonly (though not exclusively) used for pocket dirt bikes, ATVs, go karts and buggies. Approximate dimensions:
Outside Diameter: 140mm
Centre Hole Diameter: 26.1mm
Mounting Hole (centre-centre): 33mm
Bolt Hole: 5.2mm
Thickness: 3.2mm