Case size: 40 mm
Material: steel
Movement: automatic, caliber 3185
Year: circa 1998
Crystal: sapphire crystal
Bracelet: Oyster bracelet, folding clasp, ref. 78790-U4/501B
Reference number: 16710
Serial number: U.655.830
Movement number: 3 7979466
Case number: 16710
Accompanied by: certificate, box
Please keep in mind that an overhaul might be needed, since no service history is available.
The Rolex GMT Master was developed in cooperation with Pan Am. As in the 1940s and 50s flying distances got longer and the pilots travelled through multiple time zones, Pan Am asked Rolex in the 1950s to develop a watch which could tell different times simultaneously.
The watch was designed as an aviator watch and the newly introduced fourth hand allowed the display of an additional time, with the corresponding numbermarkings on the outer bezel. Pilots used the second time to display the Greenwich Mean Time (GMT), which led to the name Rolex GMT-Master.