This is a A-1306146C1 Sprocket Assembly PN: 1306146C1Main Description As Following : A-1306146C1 Sprocket Assembly P.N: 1306146C1 Dim A (1): 26 Tooth Double SprocketDim B (2): 6.625" O.D.Dim C (3): 3.625" Bolt Hole CentersDim D (4): 2.887" I.D. Crossed From: AV100668 VAPORMATIC Found in Section & Models : Headers/Platforms/Feeder House > Corn Head Parts, Case-IH HEAD, CORN: 1054, Case-IH HEAD, CORN: 1063, Case-IH HEAD, CORN: 900 SERIES Associated Items : New Also This is An Aftermarket Product And : Dim A (1): 3.625" Bolt Hole Centers Inside Diameter: 2.887" Outside Diameter: 6.625" Teeth: 26 Double Sprocket