Even Further proving its mastery of chronographs and precisely significant-frequency precision, ZENITH unveils the DEFY El Primero 21 using a new El Primero calibre beating at a phenomenal fee of 50Hz for an precise one/a centesimal of the next chronograph operate. Motivated by British pilot’s watches in the seventies, Hamilton’s https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/