Even Further proving its mastery of chronographs and particularly higher-frequency precision, ZENITH unveils the DEFY El Primero 21 which has a new El Primero calibre beating at a phenomenal price of 50Hz for an correct 1/a hundredth of the 2nd chronograph purpose. Declaring the winner in the race to make https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/