Even Further proving its mastery of chronographs and specifically high-frequency precision, ZENITH unveils the DEFY El Primero 21 with a new El Primero calibre beating in a phenomenal fee of 50Hz for an precise one/100th of a 2nd chronograph operate. Now many years since its debut, TAG has Yet again https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/