What year did Zenith introduce its high-frequency wristwatch with an integrated chronograph?

Zenith introduced its high-frequency wristwatch with an integrated chronograph in 1969. This watch was notable for featuring the El Primero movement, which operated at an impressive frequency of 36,000 vibrations per hour. This high frequency allowed for more precise timekeeping and the ability to measure elapsed time to the nearest tenth of a second, which was a remarkable advancement in watchmaking at the time.

The El Primero movement represented a significant technological achievement in the watch industry, setting a new standard for automatic chronographs and influencing many subsequent designs. Zenith’s decision to market this watch not only showcased their innovative capabilities but also solidified their reputation as a leader in the luxury watch segment.

It's important to note that this innovation came at a time when the Swiss watch industry was responding to the threat of quartz movement technology. Zenith’s commitment to automatic mechanical movements through the El Primero reflected the brand’s dedication to craftsmanship and precision, which appealed to watch enthusiasts and collectors alike.