Even More proving its mastery of chronographs and precisely high-frequency precision, ZENITH unveils the DEFY El Primero 21 with a new El Primero calibre beating at a phenomenal level of 50Hz for an accurate one/one centesimal of a 2nd chronograph function. Be celebration correct: Bear in mind the basic policies: https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/