This is a A-50X25 Sprocket PN: 50X25Main Description As Following : A-50X25 Sprocket P.N: 50X25 Hub Required: XInside Diameter: 2"Outside Diameter: 5.323"Teeth: 25 Crossed From: WSS105025 , , 20005025 , , 20005025 , , 2827-40527 JOHN DAY , 3016-0196 , , 6713-52113 JOHN DAY , 673-S80502500 , , 673S80502500 , 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: 5.323" Teeth: 25