The Fleurier 139 watch movement, also known as calibre 581, features a pin-lever escapement and a ratchet on the dial side. It incorporates a crown mechanism with a rocker bar and utilizes the Kif-Duofix combined setting for the escapement wheel if equipped with 17 jewels. Since 1996, the movement has been consistently designated as calibre 581, incorporating a calendar- and dual-time module based on ETA 2671/2678. The movement is manually wound and includes a sub second function. It was predominantly utilized during the period around 1960.