The Femga 520 watch movement features a straight lever escapement and an indirect minute, as well as a hand friction clutch on the barrel. It incorporates a ratchet on the dial side and a crown mechanism with a rocker bar. The movement is built with a two-layer base plate. Notable functions of the Femga 520 movement include manual winding and a sub-second display. These specifications were commonly used in watches produced around 1935.