ETA SA 12

The caliber 12 is an automatic chronograph movement manufactured by ETA SA. It was introduced in 1969 as part of the Chronomatic family, developed collaboratively by Heuer, Buren/Hamilton, Breitling, and Dubois-Depraz under Project 99. The movement measures 7.7mm in height with a micro-rotor, operates at 21,600 vph, and features a bi-compax chronograph layout with Incabloc shock protection. It was used in Heuer Daytona, Monaco, Carrera, and Autavia models before production ended in the late 1970s.