Aftermarket Main drive double sprocket from Gear Box . Sprocket has 17 / 17 teeth, with a 1.253" bore size and used with 60 chain. Fits John Deere round balers Models 330, 335, 375, 430, 530, 435,  535, 466, 566, 446, 546, 456, 556, 467,567, 457, 557, 447, 547, 448, 458, 558. 

Bore  1.253"
Bore Type  - Hex
Chain Size  - 60
Replaces  - AFH205784, AE39301

OEM# for reference only