Even Further proving its mastery of chronographs and specifically significant-frequency precision, ZENITH unveils the DEFY El Primero 21 having a new El Primero calibre beating at a phenomenal rate of 50Hz for an accurate one/100th of a second chronograph function. The Speedmaster gets all the like in Omega’s chronograph lineup, https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/