The Rolex Cosmograph Daytona is a mechanical chronograph wristwatch designed to meet the needs of racing drivers by measuring elapsed time and calculating average speed. Its name refers to Daytona, Florida, where racing flourished in the early 20th century. It has been manufactured by Rolex since 1963 in three distinct generations (or series); the second series was introduced in 1988, and the third in 2000. While cosmetically similar, the second series introduced a self-winding movement (the first series is hand-wound), and the third series brought manufacture of the movement in-house to Rolex. The first series included an "exotic" variant dial now known as the Rolex "Paul Newman" Daytona, named after the famed actor, who received the watch as a gift from his wife, Joanne Woodward, and popularized it by wearing it consistently while pursuing his racing career. Years later, the actor's watch, which had been gifted to his daughter's boyfriend in 1984, was sold in 2017 at the Phillips New York Winning Icons auction for a record (for wristwatches) $17.8 million. The current Cosmograph Daytona is equipped with a tachymetric scale, a sweep seconds hand for reading to 1/8 of a second, and elapsed-time hours and minute displays. Its Rolex calibre 4130 has the particularity of using a vertical (rather than lateral) clutch to activate the chronograph, and was engineered to feature a reduced number of components for greater reliability. The minute and hour systems of this series is simplified with one single mechanism placed on a side of the movement (used to consist of two mechanisms placed on both sides of the movement). With a 40mm case, it is available in a variety of materials. History There have been three series of the Cosmograph Daytona. Prior to the release of the "Daytona", Rolex produced chronographs using movements sourced from outside manufacturers housed in conventional and, starting in the 1940s, Oyster cases. Rolex introduced a more modern chronograph in 1955, designated Reference 6234, and manufactured approximately 500 per year until 1961, the year it was discontinued. The dial of Reference 6234 was not marked "Cosmograph" or "Daytona". The Reference (model) number is marked on the side of the case at the 12 o'clock position, where it is hidden under the strap lugs. Reference 6234 has three smaller sub-dials, to mark the passage of seconds up to 60 seconds (at the 9 o'clock position), minutes up to 30 minutes (at the