This is a A-50X54 Sprocket PN: 50X54Main Description As Following : A-50X54 Sprocket P.N: 50X54 Hub Required: XInside Diameter: 2"Outside Diameter: 11.106"Teeth: 54 Crossed From: WSS105054 , , 3016-0221 , , 6713-53263 JOHN DAY 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: 11.106" Teeth: 54