Description Idler sprocket, 17 teeth, 1/2" bore, RC50 chain. John Deere: Combines: 55, 95, 105, 3300, 4400, 6600 & 7700. May be used for AH87204, AH98176. New Holland: Combines: TR70. Mower Conditioners: 477 and 478. Windrowers: 1100; 707W windrow attachment. This item is a suitable alternative for the following: TP-AH21440, 216850, A-AH21440, A-IS501712, AAH21440, AH87204, AH98176, AIS501712