Rolex used the Zenith El Primero Chronograph till the year 2000 in their Daytona watches now known as the Zenith Daytonas. It was the first high beat automatic chronograph ever made back in 1969.
Below are a few links of the history of the El Primero movement and it’s significance not only for Zenith but for all of horology.
The watch in the video is my personal Rainbow made in the mid to late 1990’s. My watch has never been serviced and despite that it still runs at COSC specifications.
In my humble opinion the El Primero is the greatest chronograph ever made largely due t its history.
MUST WATCH! How Charles Vermot saved the El Primero • Zenith Watches - Disco...
Another must watch • How the legendary ZENI...