Even More proving its mastery of chronographs and precisely superior-frequency precision, ZENITH unveils the DEFY El Primero 21 with a new El Primero calibre beating at a phenomenal amount of 50Hz for an exact one/one hundredth of a second chronograph function. Equipment Patrol editors selected the Blancpain Air Command among https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/