Zenith
Calibre El Primero 3604
Automatic chronograph
Specifications
- Maker
- Zenith
- Type
- Automatic chronograph
- In-house
- Yes
- Power reserve
- about 60 h
- Frequency
- 36,000 vph (5 Hz)
Sources
- Official Zenith retrieved October 18, 2026
Used in
| Watch | Ø | Thickness | Lug-to-lug |
|---|---|---|---|
| Zenith Chronomaster Open (steel) 03.3300.3604/21.M3300 | 39.5 mm | 13.6 mm | — |
| Zenith Chronomaster Open (18 ct rose gold) 18.3300.3604/69.C922 | 39.5 mm | 13.6 mm | — |