Model: Cosmograph Daytona Reference: 6265 Date: Purchased 4th November 1981 Movement: 17-jewel Cal.727 manual wind, column wheel, free-sprung Gyromax Microstella balance, adjusted to 3 positions Dial: Sunburst silvered, applied polished baton hour markers, black outer 1/5th second divisions, black subsidiary dials at 3, 6 and 9 for seconds, 30 minute and 12 hour recording, polished baton hands with luminous inserts, black centre chronograph hand, Sigma symbols either side of T Swiss T Case: Brushed and polished tonneau form, screw down back, screw down crown flanked by twin screw down buttons, tachymetre to bezel, No.3436643 Strap/Bracelet: Fitted brushed and polished folded 7825 Oyster link, end links stamped 387 Buckle/Clasp: Signed folding clasp Signed: Case, dial & movement Size: 36mm Accompaniments: Rolex box, Guarantee 注脚 In 1969 Rolex replaced the first Oyster Cosmograph 6240 with both the reference 6263 and 6265. Although similar in many aspects, the main differentiating factor between the two new references was the choice of bezel. The 6263 featured a black aluminium insert with printed tachymetre, whereas the 6265, as with the current lot, presented to the market a smooth engraved metal bezel. The current example is fitted with a 'sigma dial', a nickname for watches that feature a lowercase letter sigma σ from the Greek alphabet below 6 o clock. This signifies the hour markers being made out of 18K white gold. Introduced in the 1970s, this feature can be found on watches as late as 2003.