More Proving its mastery of chronographs and especially substantial-frequency precision, ZENITH unveils the DEFY El Primero 21 using a new El Primero calibre beating at a phenomenal price of 50Hz for an exact 1/a hundredth of the next chronograph function. Gear Patrol editors chose the Blancpain Air Command amongst their https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/