This is a A-40X72 Sprocket PN: 40X72Main Description As Following : A-40X72 Sprocket P.N: 40X72 Hub Required: XInside Diameter: 2"Outside Diameter: 11.752"Teeth: 72 Crossed From: 20004072 , , 20004072 , , 3016-0179 , , 6713-51213 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: 11.752" Teeth: 72