Even More proving its mastery of chronographs and specially superior-frequency precision, ZENITH unveils the DEFY El Primero 21 which has a new El Primero calibre beating in a phenomenal amount of 50Hz for an accurate 1/100th of a next chronograph function. Gear Patrol editors selected the Blancpain Air Command among https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/