The Gruen 380 is a mechanical watch movement featuring a unique crown mechanism with a rocker bar. It also has variants that incorporate a ratchet wheel on the back side, and some of these variations include a click on the dial side and a functionless crown wheel. The exact assignment of these variants to the numbers 1237, 1238, 1245, 1249, and 1269 is not widely known, except for the AS 1245, which is confirmed to have a ratchet wheel on the back side. The movement includes the following functions: manual wind, sub second, and period used around 1950.