The General 31 watch movement is an open face calibre available with options such as a bimetallic screw balance and a Breguet hairspring. It was produced as pocketwatch calibres in sizes ranging from 18.5 to 19''', with heights of 4.2, 5.0, and 5.9mm. This movement exhibits various bridge layouts, two base plates with differing dial-feet positions, and two slightly differing setting-lever springs. The assignment of these differences to the FHF movement groups and specific calibre designations (FHF 1 to 14, FHF 1144, 2144, 2146, 4144, 4146) remains partially known. However, a comparison of the corresponding calibres provides an understanding. The General 31 movement offers functions such as stem winding and setting, as well as a sub-second display. It was commonly used during the period around 1940.