FHF 4144

open face calibre options: bimetallic screw balance, Breguet hairspring These pocketwatch calibres were made with 18.5 und 19" , and the heights 4.2, 5.0, and 5.9mm. There are various bridge layouts, two base plates with differing dial-feet positions, and two slightly differing setting-lever springs. The assignment of such differences to the groups FHF 1 to 14 and the calibres FHF 1144, 2144, 2146, 4144, 4146 is just partially known. But comparing the according calibres gives an imagination. FHF 1 to FHF 16 designate movement groups containing calibres of different dimensions; individual designations start with FHF 22.