They feature an important novelty both aesthetically and functionally, based on the experience of the previous reference (ref.6240). The new models are equipped with screw-down chronograph pushers to achieve water resistance and are used 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.
Specifically this model of 6263 produced in 1979 with serial number 60XXXXX, mounts a black dial, the inscription "Cosmograph" placed above the counter at six o'clock. Metal bezel with black plastic insert and tachymeter scale printed in white. Watch with 37mm diameter Yellow Gold case with Yellow Gold strap and Valjoux 727 movement.
Preserved in Excellent condition.
