Additional Proving its mastery of chronographs and particularly higher-frequency precision, ZENITH unveils the DEFY El Primero 21 by using a new El Primero calibre beating at a phenomenal fee of 50Hz for an correct 1/a centesimal of the 2nd chronograph functionality. The phrase “chronometer” took on a slightly broader that https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/