Calibre 2236 Is fitted with a Syloxi hairspring that is produced by Rolex and patented. This silicon hairspring has a patented geometry that ensures the calibre’s regularity in almost any situation. 6 miles, or fifty five.seven km) at the conclusion of a six months’ voyage. (The geographical mile is outlined https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/