Additional Proving its mastery of chronographs and specifically higher-frequency precision, ZENITH unveils the DEFY El Primero 21 with a new El Primero calibre beating in a phenomenal charge of 50Hz for an accurate one/one hundredth of a next chronograph functionality. Influenced by British pilot’s watches from the nineteen seventies, Hamilton’s https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/