Even Further proving its mastery of chronographs and especially high-frequency precision, ZENITH unveils the DEFY El Primero 21 that has a new El Primero calibre beating at a phenomenal charge of 50Hz for an accurate 1/one hundredth of the second chronograph operate. Now many years because its debut, TAG has https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/