With Rolex green presentation box.
The present watch is from the fourth, so-called "Mark IV" or "Mk 4" series of the "double red" Sea-Dweller, in production between around 1974-1977 and distinguished by the printing on its dial.
The "double red" designation is written directly on the dial and often a mid red colour, less intense than on the "Mk 2" for example. The two double red lines show different sizes: the second line, "SUBMARINER 2000", is smaller than the first line "SEA-DWELLER". The 5 tips and the oval at the base of the Rolex crown are clearly defined. The overall impression of the fonts is less distinct in its application, when closely inspected the printing appears to be made up of a series of dots, rather than direct brush strokes or application.
The celebrated Sea-Dweller reference 1665 launched in 1967 was the first wristwatch designed for use in saturation diving, fitted with a Rolex patent valve in the band and guaranteed waterproof to 610 meters depth. The valve was first developed on the Submariner model and allows helium and other gases to escape, enabling the watch to withstand compression.