Further Proving its mastery of chronographs and specifically high-frequency precision, ZENITH unveils the DEFY El Primero 21 which has a new El Primero calibre beating in a phenomenal amount of 50Hz for an accurate one/100th of the next chronograph purpose. Racing watches can come in several forms and get inspiration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/