ETA SA A31-111

The A31.111 is an automatic movement manufactured by ETA SA in Switzerland, based on the established ETA 2892-A2 framework. It displays hours, minutes, and seconds with a date complication. The caliber features a Nivachron hairspring and Nivashock anti-shock system. It was developed after ETA ceased supplying movements to brands outside the Swatch Group, and Mido uses this movement under their own caliber designation 72.