ETA SA A31-L11

The ETA A31-L11 is an automatic movement manufactured by ETA SA in Switzerland, based on the established ETA 2892-A2. It delivers a 72-hour power reserve thanks to an upgraded mainspring alloy and features a ball bearing rotor. The movement incorporates a silicon hairspring for improved magnetic resistance. Longines uses this caliber as the base for its L888 and L888.4 calibers, and it remains in production for various Swatch Group brands.