Needle Bearing Idler Sprocket, Bore Diameter 1 in, Chain Number 50, Sprocket Material Steel, Number of Teeth 17, Outside Diameter 3.72 in, Bearing Material Steel, Bearing Type Needle Roller, For Chain Pitch 5/8 in, For Number of Strands Single, For Use With Tightener Shaft, Hub Diameter 2 1/4 in, Hub Projection 0.657 in, Length through Bore 1 in, Lubrication Grease