The A. Schild 501 is a mechanical watch movement with an open face calibre. It features a winding gear with a rocker on the back side and a barrel with Geneva stopwork. The movement incorporates various functions, including a timer with 1s (0.1s), 60s, and 60min indications, controlled by a pillar wheel. Additionally, it includes an addition timer, offering enhanced functionality. The watch movement is stem wind, and it has sub dials for 1/10 seconds, seconds, and minutes. Notably, it employs a stop over wheel on the escape-wheel arbor for 1/10 seconds precision. This movement has been in use since 1962.