The Fleurier 72 watch movement, which was in use around 1955, is a manual wind movement equipped with a sweep second function. The watch also features a day and date calendar, with the day set by a pusher at 8:30h and the date set by a pusher at 9:30h. The movement incorporates an Incastar regulator, a unique system that utilizes a free oscillating hairspring. The end of the spring is fixed between two rollers, allowing for the actual adjustment of its length. This design eliminates isochronism error that could be caused by the gap between the regulator pins.