The Cyma Tavannes 670 is an open face calibre watch movement produced from 1962 onwards. It features a winding gear with a rocker on the back side and a barrel with Geneva stopwork. The movement incorporates a timer with functions including 1s (0.1s), 60s, 60min, pillar wheel activation, and an addition timer. It also includes subdials for 1/10 seconds, seconds, and minutes. Other notable features include a stop over wheel on the escape-wheel arbor for measuring 1/10 seconds and, in early samples, an additional balance brake.