The Precision of the Rolex Superlative Chronometer is of the purchase of −2/+2 seconds each day – the rate deviation tolerated via the brand name for the completed view is appreciably smaller than that accepted by COSC for Formal certification in the movement alone. The Superlative Chronometer status is symbolized https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/