This is a A-50X30 Sprocket PN: 50X30Main Description As Following : A-50X30 Sprocket P.N: 50X30 Hub Required: XInside Diameter: 2"Outside Diameter: 6.321"Teeth: 30 Crossed From: WSS105030 , , 20005030 , , 20005030 , , 3016-0201 , , 6713-52363 JOHN DAY , 673-S80503000 , , 673S80503000 , 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: 6.321" Teeth: 30