The Unitas 347 watch movement is an open face calibre which offers various options such as a bimetallic screw balance and a Breguet hairspring. These pocketwatch calibres are available in sizes 18.5 and 19''', with heights ranging from 4.2mm to 5.9mm. There are different bridge layouts, two base plates with varying dial-feet positions, and two slightly differing setting-lever springs. While the complete assignment of these differences to the FHF groups is not fully understood, comparing the corresponding calibres provides some insight. The Unitas 347 movement falls within the FHF 1 to FHF 16 movement group, with individual designations starting from FHF 22. This movement offers stem wind and set functionality, a sub-second dial, and was commonly used around 1940.