Even Further proving its mastery of chronographs and specially high-frequency precision, ZENITH unveils the DEFY El Primero 21 that has a new El Primero calibre beating at a phenomenal rate of 50Hz for an correct one/100th of the next chronograph functionality. To promote the art of watchmaking to as Many https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/