These models feature an important novelty both aesthetically and functionally, based on the experience of the previous ref. (6240) these new chronographs are equipped with screw-down chronograph pushers.
This type of pushers are used to achieve water resistance and are employed with the new 7mm Triplock winding crown; despite these changes and Rolex's efforts to achieve a water-resistant chronograph the maximum depth will be 50m/165ft.
The life of the two models is mirrored the only difference is aesthetic-they are differentiated only by the bezel.
The 6263 has a black plastic bezel with tachymeter scale printed in white, the 6265 mounts a metal bezel with tachymeter scale engraved in black.
The Daytona inscription (featured since the second half of the 1970s) is always printed in red above the counter at 6 o'clock.
The "Paul Newman" variant without the Daytona inscription is only available for a narrow period from about 1969 to 1972.
The movement adopted is the Valjoux Caliber 727, which will remain unchanged until the end of production. Apart from the dial there will be minor changes on the graphics of the bezels, pushers and crowns.