Still located in the premises where it was born in 1865, Zenith is celebrating its 150th anniversary by introducing an exceptional watch imbued with the visionary genius of its founder, Georges Favre-Jacot.

Genius was indeed required to transpose the fusée and chain system borrowed from historical marine chronometers to the tiny space of a wristwatch.
This highly complex device serves to compensate for the progressive reduction in the force of the barrel as the power reserve is discharged, and to maintain the perfect stability of the force with no loss of amplitude. In concrete terms, the mainspring transmits its energy to the helicoidal fusée devised by Zenith via an 18-cm chain that wraps itself around the barrel.
By adjusting for variations in tension, the fusée ensures the regularity of the force distributed to the gear train and then to the silicon escape wheel. 150-piece limited edition.

Mechanical hand-wound constant-force El Primero 4810 calibre with fusée and chain transmission connected to the barrel, COSC-certified chronometer, 36,000 vph, 797 parts (including 575 for the fusée and chain), 30 jewels, 50-hour power reserve.

Source: Europa Star March 2015 Magazine Issue