This is a A-40X36 Sprocket PN: 40X36Main Description As Following : A-40X36 Sprocket P.N: 40X36 Hub Required: XInside Diameter: 2"Outside Diameter: 6.015"Teeth: 36 Crossed From: WSS104036 , , 20004036 , , 20004036 , , 3016-0164 , , 6713-50863 JOHN DAY , 673-S80403600 , , 673S80403600 , 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: 6.015" Teeth: 36