Further Proving its mastery of chronographs and particularly higher-frequency precision, ZENITH unveils the DEFY El Primero 21 with a new El Primero calibre beating in a phenomenal amount of 50Hz for an accurate one/a centesimal of a second chronograph operate. The Speedmaster receives many of the adore in Omega’s chronograph https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/