For the Daytona’s 25th anniversary, Rolex surprised the public at the 1988 Basel fair by introducing the first self winding chronograph model in its history. The newly launched reference 16520 was powered by a derivative of Zenith’s El Primero calibre, substantially modified by Rolex. It was also the first Daytona to be fitted with a sapphire crystal and a new, larger diameter, now being 39 milimeters. It was an immediate success. The very first generation, like the present example, feature the very rare 200 graduation bezel and the most sought after specimen are equipped with an enamel coated dial. The Cosmograph designation is separated from the first four lines which lends it the nickname “floating” or in Italian “Staccato”.Being from the very first R-series, the present example also features the correct all satin finish Oyster bracelet, making it a must-have for the discerning Daytona collector, despite still being a young timer.