The Rolex GMT-Master was originally manufactured as a pilot’s watch, as a tool for PanAm pilots. Three times zones are represented by the GMT hand, and by the bezel insert when rotated in relation to the primary time zone indicated by the hours, minutes, and seconds hands. Of all of the variations produced, this example was manufactured in 1977, 5.2M serial number, boasting a pristine mark 5 dial with heavy and consistent yellow patina and a flawless matte surface. The brilliantly bright Pepsi insert is very good condition, with no noticeable scratches or blemishes, and the case and bracelet are unpolished. This watch has been fully serviced.