1976 Rolex Daytona (Ref. 6265) Black "Sigma" Dial

Rolex first introduced the Cosmograph in 1963 in steel, 14k, and 18k yellow gold with a design that was solely focused on automobile racing. The Units Per Hour bezel allowed for the tracking and measuring of average speed and lap times, making for a truly useful tool for racing drivers in the 20th century. Rolex, being the same marketing powerhouse back then as they are today, knew the American market would be their most effective demographic as racing in America was on the rise in the 60s-70s. Effectively, in 1964, the Rolex Cosmograph was branded “Daytona” after the famous race, the 24 Hours of Daytona, and the rest is history.

The Daytona saw its first major update in late 1969 when Rolex decided to bring its Oyster technology to the Cosmograph. Accompanying the "Oyster" text on the dial, the case crown was upgraded to a 7mm trip-lock crown, and the most significant upgrade was the introduction of the screw-down chronograph pushers, which is a function we still see today in the modern Daytona offering from Rolex. While the case size of this new model was the same as its predecessor at 36mm, the larger crown and more robust pushers greatly increase the watch's wrist presence. 

A Sigma dial is a Rolex dial named for the letters printed at the bottom of the dial at the 6 o'clock position. Most Rolex dials in this era are commonly marked with “T Swiss T,” under the 6 o'clock marker; however, a Sigma dial is marked “σ T SWISS T σ.” This signifies the use of gold components within the dial.