This is a A-50X23 Sprocket PN: 50X23Main Description As Following : A-50X23 Sprocket P.N: 50X23 Hub Required: XInside Diameter: 2"Outside Diameter: 4.922"Teeth: 23 Crossed From: WSS105023 , , 20005023 , , 20005023 , , 2827-40327 JOHN DAY , 3016-0194 , , 6713-52013 JOHN DAY , 971-20005023 , , 97120005023 , 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: 4.922" Teeth: 23