Dubois Dépraz Calibre 11-12

The Calibre 11-12 (Chronomatic) was the world's first automatic chronograph developed as a modular design. Created through a consortium of Heuer-Leonidas, Breitling, Büren, and Dubois Dépraz in 'Project 99', it combined a Büren microrotor movement with a Dubois Dépraz chronograph module. Technical specifications were written by Gérald Dubois and Hans Kocher. Launched in 1969 alongside the Zenith El Primero and Seiko 6139. Used in iconic watches including the Heuer Monaco, Heuer Autavia, Breitling Chronomat, and Hamilton Chrono-matic. Over 350,000 units were produced.