Further More proving its mastery of chronographs and particularly significant-frequency precision, ZENITH unveils the DEFY El Primero 21 with a new El Primero calibre beating in a phenomenal fee of 50Hz for an accurate 1/one centesimal of a second chronograph function. The Speedmaster receives every one of the like in https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/