The Oyster Perpetual GMT-Master is the watch for airline pilots, chosen by serious travellers and professionals who fly the world. The Rolex GMT Master is a line of the Rolex Professional Watch Collection designed in collaboration with Pan Am Airways and issued by the airline to their crews on long haul-flights, first launched in 1954. This GMT hand enabled the crews to set the watch to GMT (Greenwich Mean Time) or another time zone using the rotatable 24 hour scale bezel so that a second time zone could be read.