AHN60

Hubert Herr 3 Piece hand nut set for 1 day cuckoos.
Inside diameter of nut with square hole is approximately 2.3mm (.093 Inch). Inside diameter of small nut is approximately 2.2mm (.090 Inch). Generally used on Herr clocks made within the last 20 years. Herr is usually marked on the back of the movement.