The Precision of the Rolex Superlative Chronometer is from the order of −2/+2 seconds a day – the rate deviation tolerated because of the brand for your finished view is noticeably smaller than that accepted by COSC for Formal certification on the motion on your own. The Superlative Chronometer position https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/