Even More proving its mastery of chronographs and exclusively significant-frequency precision, ZENITH unveils the DEFY El Primero 21 having a new El Primero calibre beating in a phenomenal rate of 50Hz for an accurate one/one hundredth of a 2nd chronograph functionality. Inspired by British pilot’s watches through the seventies, Hamilton’s https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/