Zenith

Heritage

Home of the El Primero — the world's first high-frequency automatic chronograph.

In 1969 Zenith introduced the El Primero, the first integrated automatic chronograph movement to beat at 36,000 vph — capable of measuring 1/10th-of-a-second precision. When the quartz crisis nearly killed mechanical watchmaking, a Zenith watchmaker hid the El Primero tooling rather than destroy it, preserving the caliber that would later power Rolex Daytonas.