The Precision of a Rolex Superlative Chronometer is of the purchase of −2/+2 seconds on a daily basis – the rate deviation tolerated through the manufacturer for a concluded look at is noticeably lesser than that acknowledged by COSC for Formal certification in the movement by yourself. The Superlative Chronometer https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/