More Proving its mastery of chronographs and specifically higher-frequency precision, ZENITH unveils the DEFY El Primero 21 using a new El Primero calibre beating at a phenomenal level of 50Hz for an accurate 1/one hundredth of the next chronograph purpose. Now a long time since its debut, TAG has once https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/