Composite Idler Sprocket with Bearing, Bore Diameter 17 mm, Chain Number 50, Sprocket Material Fiberglass-Reinforced Nylon, Number of Teeth 15, Outside Diameter 3.34 in, Bearing Material Chrome Steel, Bearing Number 6203-2RS, Bearing Type Ball, For Use With Sprocket Assemblies, T-Max Tensioner, Hub Diameter 1 3/4 in, Length through Bore 1 in, Lubrication Mobil Polyrex EM, NLGI No. 2, Material Grade 6/6, Maximum Operating Temperature 225 Degrees F