The A. Schild 636 watch movement was produced during the period of 1925 to the late 1930s by Alpina Gruen Gilde. It features a bimetallic screw balance and a Breguet hairspring, ensuring precise timekeeping. The movement is equipped with a straight lever and a stem mechanism without a setting-lever spring. This manual wind movement incorporates a sub-second function and has been in use since its introduction in 1925.