This is a A-AH145940 Sprocket, Row Unit PN: AH145940Main Description As Following : A-AH145940 Sprocket, Row Unit P.N: AH145940 Chain: 50Inside Diameter: 1.130" HexOutside Diameter: 13.110"Teeth: 64 Crossed From: AV103496 VAPORMATIC Found in Section & Models : Headers/Platforms/Feeder House > Corn Head Parts, John Deere HEAD, CORN: 1293 (SN <665400), John Deere HEAD, CORN: 493 (SN <665200), John Deere HEAD, CORN: 494 (SN <665200), John Deere HEAD, CORN: 594 (SN <665400), John Deere HEAD, CORN: 693 (SN <665400), John Deere HEAD, CORN: 693SH (SN <665400), John Deere HEAD, CORN: 893 (SN <665400), John Deere HEAD, CORN: 894 (SN <665400) Associated Items : New Also This is An Aftermarket Product And : Chain: 50 Inside Diameter: 1.130" Hex Outside Diameter: 13.110" Teeth: 64