Calibre 2236 Is equipped having a Syloxi hairspring that is made by Rolex and patented. This silicon hairspring features a patented geometry that assures the calibre’s regularity in almost any situation. six miles, or fifty five.seven km) at the end of a 6 months’ voyage. (The geographical mile is described https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/