Zenith SA is a high-end luxury Swiss watch manufacture started in 1865 by Georges Favre-Jacot at the age of 22, in Le Locle in the canton of Neuchâtel. Zenith was purchased by LVMH in November 1999, becoming one of several brands in their watch and jewellery division. The CEO of the company is Jean-Frédéric Dufour, formerly of Chopard.
Zenith has a long reputation for the quality and precision of their watches. It is one of few remaining Swiss watch manufacturers that still produce their own movements in-house.
The El Primerocalibre, which was first released in 1969, though still produced today, was one of the first automatic chronograph movements and has a frequency of 36,000 alternations per hour (5 Hz). This high rate allows a resolution of 1⁄10 of a second and a potential for greater positional accuracy over the more common standard frequency of 28,800 alternations per hour (4 Hz). The El Primero was honoured with a 2012 release of the El Primero Stratos Flyback Striking 10th, limited to 1,969 pieces (in honour of the original 1969 release date), that housed the same 36,000 vph movement and a sub-dial measuring in tenths of a second to make a complete rotation every ten seconds.