Sprocket, Idler
CTPA-AH21440 Replacement Part to Fit:  John Deere For Models: 105, 3300, 4400, 4420, 55 SN 57001->, 6600, 6601, 6602, 6620, 7700, 7701, 7720, 95 SN 9001-> 17 tooth, 1/2" bore, 50 chain  Price:  $15.36  Buyers Club Price:  $13.82