Even More proving its mastery of chronographs and specifically substantial-frequency precision, ZENITH unveils the DEFY El Primero 21 by using a new El Primero calibre beating in a phenomenal amount of 50Hz for an correct one/100th of a next chronograph functionality. My expertise with the vendor, was really fantastic. The https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/