This is a A-AH215519 Sprocket, Row Unit, 24 Tooth / 80 Chain, Speed Up PN: AH215519Main Description As Following : A-AH215519 Sprocket, Row Unit; 24 Tooth / 80 Chain, Speed Up P.N: AH215519 Dim A (1): 24 ToothDim B (2): 8.203" O.D.Dim C (3): 1.263" Hex Hub Crossed From: AV103737 VAPORMATIC Found in Section & Models : Headers/Platforms/Feeder House > Corn Head Parts, John Deere HEAD, CORN: 1092, John Deere HEAD, CORN: 1290, John Deere HEAD, CORN: 1291, John Deere HEAD, CORN: 1293 Associated Items : New Also This is An Aftermarket Product And : Hub: 1.263" Hex Outside Diameter: 8.203" Teeth: 24