The GMT-Master is one of Rolex’s most iconic models ever made. It was a watch delivered for aviation purposes as the door to commercial aviation began opening in the late 1950s. The present watch being part of the GMT-Master series is a reference 1675 encased in a rare 18k yellow gold sheen that is not normally seen in all of Rolex’s line of production at the time. As the GMT-Master was specifically built for aviation purposes, it was a model better suited with the use of precious-metal in comparison to other tool watches such as the Submariner which was made for diving. Nicknamed the nipple dial by collectors, the watch is fitted with an unusual dial that has a slight protruding hour marker of precious materials. These dials can usually be found in black, brown, or blue.