The Precision of a Rolex Superlative Chronometer is of your order of −2/+two seconds a day – the rate deviation tolerated through the manufacturer for a completed watch is considerably scaled-down than that accepted by COSC for Formal certification on the movement alone. The Superlative Chronometer position is symbolized through https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/