Composite Idler Sprocket with Bearing, Bore Diameter 17 mm, Chain Number 40, Sprocket Material Fiberglass-Reinforced Nylon, Number of Teeth 17, Outside Diameter 2.98 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