The Precision of a Rolex Superlative Chronometer is from the purchase of −2/+two seconds each day – the rate deviation tolerated with the model to get a completed view is substantially scaled-down than that acknowledged 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/