This is a A-50X28 Sprocket PN: 50X28Main Description As Following : A-50X28 Sprocket P.N: 50X28 Hub Required: XInside Diameter: 2"Outside Diameter: 5.922"Teeth: 28 Crossed From: WSS105028 , , 20005028 , , 20005028 , , 3016-0199 , , 6713-52263 JOHN DAY , 673-S80502800 , , 673S80502800 , 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: 5.922" Teeth: 28