The Precision of the Rolex Superlative Chronometer is of your buy of −2/+two seconds each day – the rate deviation tolerated by the manufacturer for any finished look at is substantially scaled-down than that acknowledged by COSC for Formal certification of your movement alone. The Superlative Chronometer position is symbolized https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/