Calibre 2236 Is fitted using a Syloxi hairspring that is produced by Rolex and patented. This silicon hairspring incorporates a patented geometry that guarantees the calibre’s regularity in any situation. 6 miles, or fifty five.7 km) at the conclusion of a six weeks’ voyage. (The geographical mile is outlined as https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/