Further More proving its mastery of chronographs and especially high-frequency precision, ZENITH unveils the DEFY El Primero 21 having a new El Primero calibre beating in a phenomenal fee of 50Hz for an exact 1/100th of the 2nd chronograph functionality. Chronographs — with their bezels, scales and sub-dials — are https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/