The Precision of a Rolex Superlative Chronometer is on the purchase of −2/+2 seconds on a daily basis – the speed deviation tolerated with the brand name for your finished view is noticeably smaller than that accepted by COSC for Formal certification of the motion by yourself. The Superlative Chronometer https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/