The Precision of the Rolex Superlative Chronometer is with the order of −two/+two seconds per day – the rate deviation tolerated by the manufacturer for your concluded observe is noticeably lesser than that recognized by COSC for Formal certification on the movement by yourself. The Superlative Chronometer status is symbolized https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/