Gearbelt Pulley Bore Diameter 1/2 in For Belt Series SilentSync For Belt Width 25 mm For Use With 25 mm Belt Material Aluminum Maximum Bore Diameter 2 9/32 in Number of Teeth 38 Outside Diameter 3.75 in Pitch 8 mm Pitch Diameter 3.81 in Bore Type Plain Face Width 26 mm For Belt Trade Size SilentSync Hub Diameter 3 7/16 in Hub Projection 5/8 in Hub Type One Side Keyway No Keyway Depth Not Applicable Keyway Width Not Applicable Length through Bore 1 21/32 in