"An Educational guide about the heritage of British watchmaking. Horology enthusiasts of all concentrations are guaranteed to find value here." ZENITH launches the 135-Observatoire restricted version, making the acclaimed 135 calibre, serial winner with the Global Chronometry competitions, commercially obtainable for the very 1st time in its Observatory variant ! https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/