Zenith El Primero
From Chronopedia
Zenith El Primero
The El Primero 400 runs at 36,000 vibrations per hour offers a “minimum 50 hours” of power reserve. A higher beat-rate, with the balance wheel making 10 semi-oscillations (5 left and 5 right turns) per second gives greater stability and resistance against shocks, positional errors, and other factors that negatively affect the timekeeping performance.
