The Certina 321 watch movement is an open face calibre featuring a stop function with a pillar wheel. It offers two options for the frequency: 36000 A/h, where the gear ratio from the seconds wheel to escape wheel is doubled leaving the times unchanged, and it allows for the same dials for both variants. It is likely manufactured by Valjoux, although it is often listed in catalogs as the Heuer Sport 19'''F. This movement includes functions such as a timer with measurements of 60 seconds (0.2 seconds) and 30 minutes, with the option to have measurements of 60 seconds (0.1 seconds) and 30 minutes. The movement is stem wind and has a sweep second hand. It was used around the period of 1945.