Even More proving its mastery of chronographs and specially significant-frequency precision, ZENITH unveils the DEFY El Primero 21 having a new El Primero calibre beating at a phenomenal level of 50Hz for an correct 1/100th of the next chronograph operate. Chopard's Mille Miglia selection celebrates the world's most lovely race. https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/