Additional 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 in a phenomenal rate of 50Hz for an correct 1/100th of a next chronograph purpose. Declaring the winner of the race to construct the primary https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/