From the early years of production, this 16520 "Zenith" Daytona sports the sought-after 'upside down six' Tritium dial and first '78360' all matte, pre-fliplock bracelet (from October '91). Powered by the automatic 4030 calibre movement (based on Zeniths' El-Primero) these early automatic Cosmographs have proved to be some of the fastest appreciating wristwatches of the last 10 years, and this one is in beautiful condition with its original box, Rolex service history, Daytona Cosmograph booklet and wallet.