hook drive gear.........., 7.90mm (5/16") 24 teeth
# 53741
[bernette] - 320, 330, 410, 420, 430, 440
[riccar] - 1900, 1925, 2600, 2800, 2900, 2950, 3400, 3500, 3600, 4001, 4003, 414, 500, 515, 525, 555fa, 570, 571, 581, 591, 606, 666fa, 805, 806, 807, 808, 8400, 8500, 888, 906e, 9150, 9160, 9600, 9700, 9800, 9900, r650, r750, r916
