Further More proving its mastery of chronographs and exclusively high-frequency precision, ZENITH unveils the DEFY El Primero 21 using a new El Primero calibre beating in a phenomenal amount of 50Hz for an precise one/a hundredth of the 2nd chronograph functionality. The Speedmaster gets all of the love in Omega’s https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/