Even Further proving its mastery of chronographs and especially significant-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 precise one/one centesimal of the 2nd chronograph function. Now many years since its debut, TAG has https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/