Fits over the hour wheel, used as a spacer to prevent the hour wheel from moving, eliminating the possibility of the hour wheel disengaging.
Size 3 1/2 has an outside diameter of 3.50 mm.
Fits over the hour wheel, used as a spacer to prevent the hour wheel from moving, eliminating the possibility of the hour wheel disengaging.
Size 3 1/2 has an outside diameter of 3.50 mm.