Calibre 2236 Is equipped which has a Syloxi hairspring that is produced by Rolex and patented. This silicon hairspring contains a patented geometry that makes certain the calibre’s regularity in any place. 6 miles, or 55.7 km) at the conclusion of a six months’ voyage. (The geographical mile is described https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/