F.P. Journe 1520

Calibre 1520 is a manual-winding movement manufactured by F.P. Journe. Introduced in 2010, it features twin independent balance wheels oscillating in acoustic resonance, a principle theorized by Huygens in 1665. The movement includes a dual time display, remontoir d'égalité on each train, and a differential gear for consistent energy delivery, with a 42-hour power reserve. F.P. Journe remains the only modern watchmaker to successfully achieve resonance in a production timepiece. The Chronomètre à Résonance is currently in production.