WN-H63578-PEX Clean Grain Sprocket Fits John Deere 3300 4400 4420 6600 6601 6602One New Aftermarket Clean Grain Sprocket Fits John Deere Models: 3300, 4400, 4420, 6600, 6601, 6602, 6620, 6622, 7700, 7701, 7720, 7721 Also Fits: 6600 s n 3701 ,6620 s n 610300,7700 s n 2801 ,7720 s n 610500 3300 (Lower Clean Grain & Upper Lower Return Grain), 4400 (Lower Clean Grain & Upper Lower Return Grain), 4420 (Lower Clean Grain & Upper Lower Return Grain), 6600 (s n 3701 later Upper Lower Return Grain), 6601 (Upper Lower Return Grain), 6602