More Proving its mastery of chronographs and particularly high-frequency precision, ZENITH unveils the DEFY El Primero 21 using a new El Primero calibre beating in a phenomenal price of 50Hz for an exact one/one centesimal of a next chronograph operate. It absolutely was our pleasure To help you in purchasing https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/