This is a A-50X45 Sprocket PN: 50X45Main Description As Following : A-50X45 Sprocket P.N: 50X45 Hub Required: XInside Diameter: 2"Outside Diameter: 9.313"Teeth: 45 Crossed From: WSS105045 , , 3016-0216 , , 6713-53113 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: 9.313" Teeth: 45