Further More proving its mastery of chronographs and particularly significant-frequency precision, ZENITH unveils the DEFY El Primero 21 using a new El Primero calibre beating at a phenomenal amount of 50Hz for an precise one/100th of a 2nd chronograph perform. Complication: Refers to any check out motion past the simple https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/