This is a A-40X50 Sprocket PN: 40X50Main Description As Following : A-40X50 Sprocket P.N: 40X50 Hub Required: XInside Diameter: 2"Outside Diameter: 8.25"Teeth: 50 Crossed From: 20004050 , , 20004050 , , 3016-0176 , Found in Section & Models : Chains/ Sprockets/ Pulleys/ Hubs > Sprockets, (Miscellaneous) (UNDEFINED): SEVERAL Associated Items : New Also This is An Aftermarket Product And : Hub Required: X Inside Diameter: 2" Outside Diameter: 8.25" Teeth: 50