The Zenith 48.9AF watch movement was used during the period of 1968-1972. It features a Triovis micrometer regulator for precise timekeeping. The movement includes an indirectly driven minute and automatic gear integration, allowing for a low profile design. It incorporates a ratchet on the dial side, as well as a crown mechanism with a rocker bar. Furthermore, it utilizes a rather small rotor ball bearing. Differences between the 404 and 405 versions are not known. The movement functions include automatic winding, sweep seconds, day setting through an 18-24 hour change, and quickset date.