The A. Schild 1021 is a mechanical watch movement manufactured by Gruen during the period 1935-1937. It is the first Curvex calibre offered by the brand. The movement features a bimetallic screw balance and utilizes a Breguet hairspring. Gruen has incorporated their proprietary Conoruma alloy for the balance and hairspring, ensuring minimal temperature dependence. The movement offers manual winding and includes functions such as sub-seconds and center seconds.