Omega Released its Constellation Globemaster, the very first timepiece branded with the “Master Chronometer” designation, in 2015. Watches using this accolade — which now comprise the lion’s share of Omega's output — have don't just aced the tests needed for COSC chronometer certification but have already been subjected to another, https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/