Zenith El Primero 9004

Caliber 9004 is an automatic chronograph introduced by Zenith in 2017 as part of the Defy collection. It measures 1/100th of a second using dual escapements operating at 36,000 vph for timekeeping and 360,000 vph (50 Hz) for the chronograph function. The movement contains 838 parts with silicon components and a gyropendulum, delivering 50 hours of power reserve for time and 5 hours for the chronograph. It remains in production.