Calibre 2236 Is equipped by using a Syloxi hairspring that is made by Rolex and patented. This silicon hairspring has a patented geometry that guarantees the calibre’s regularity in any posture. six miles, or fifty five.seven km) at the conclusion of a six months’ voyage. (The geographical mile is defined https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/