Even Further proving its mastery of chronographs and particularly large-frequency precision, ZENITH unveils the DEFY El Primero 21 that has a new El Primero calibre beating at a phenomenal fee of 50Hz for an exact one/one centesimal of the second chronograph functionality. Complication: Refers to any look at movement past https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/