Initially presented in white gold and then in platinum, Greubel Forsey's GMT Earth is now offered in a 45.50 mm titanium case. This light and hypoallergenic material (as well as being insensitive to temperature variations and eight times more resistant than gold and platinum) is used not only for the case, but also for the bridges, the GMT adjustment button (located at 10 o'clock), the crown and the folding clasp of the rubber strap. The partially visible dial on the movement is black and shows the off-centre hours/minutes/seconds dial, the power reserve display (at 3 o'clock), the 24-second tourbillon device inclined by 25 degrees (at about 6 o'clock), the three-dimensional terrestrial globe (with day/night indication) at 8 o'clock and the GMT function at 10 o'clock. The terrestrial globe is also visible from the side, thanks to a sapphire window on the case middle. Lastly, universal time is displayed on the caseback: the 24 time zones indicate the UTC time of 24 reference cities, with those with time changes (from solar to legal and vice versa) having a white background. The movement used (36.40 mm in diameter, 11.55 mm thick, 453 components, 60 jewels, 21,600 vibrations per hour, double barrel, 72-hour power reserve, variable inertia balance), made in-house, is mechanical with manual winding. The watch is guaranteed water-resistant to a pressure of 3 atmospheres.
