Unique edition of 66 pieces. 11 pieces in white gold. Hand-wound movement with 3 patents GMT. 2nd time zone. Rotating globe with universal time and day-and-night. Universal time on 24 time zones. Cities observing summer time. Lateral window showing the equator and southern hemisphere. GMT pusher. Quadruple Tourbillon. Hours and minutes. Small seconds. Power-reserve. Movement : 705 parts. Four tourbillon cages : 260 parts. Total weight of the cages : 2.25 g. Spherical differential : 28 parts. Number of jewels: 84, Olived-domed jewels in gold chatons. Chronometric power reserve: 72 hours. Barrels: Three series-coupled fast-rotating barrels (1 turn in 3.2 hours), one of which is equipped with a slipping spring to avoid excess tension. Balance Wheel: Variable-inertia with white gold mean-time screws. Frequency: 21600 vibrations/hour. Balance spring: Phillips terminal curve, Geneva-style stud. Main plate: Nickel silver, frosted and spotted with polished bevelling and countersinks, straight-grained flanks, nickel-palladium treatment. Bridges: Nickel silver, frosted and spotted, polished bevelling and countersinks, straight-grained flanks, nickel-palladium treatment. Gold plate engraved with the individual number. Flat black polished gold plates with reliefengraved text, polished bevelling and countersinks, straight-grained flanks. Four flat black polished steel tourbillon bridges, hand-polished bevelling and countersinks, straight-grained flanks. Inner tourbillons: Inclined at a 30° angle, 1 rotation per minute Outer tourbillons:1 rotation in 4 minutes. Hand-bevelled and openworked cage pillars. 1 gold counterweight per double cage bearing the individual number. Gearing: Involute circle profile. Conical gearing with profiled teeth. Displays: Hours and minutes, Small seconds (mean performance), 72-hours power reserve on a sector, 2nd time zone GMT, 24 time zones universal time, Rotating titanium globe with universal time, Cities observing summer time, Day-and-night. Case: In white gold with asymmetrical convex synthetic sapphire crystal. Transparent back with asymmetrical convex synthetic sapphire crystal. Lateral window with shaped synthetic sapphire crystal. Three-dimensional, variable geometry-shaped lugs. Raised polished engraving GMT Quadruple and Greubel Forsey on a hand-punched background. Gold security screws. Polished bezel, caseband with hand-finished straight graining. White gold GMT pusher with raised engraving on a handpunched background. Hand-engraved individual number. Crown: In white gold with engraved and black lacquered GF logo Dial: Multi-level in gold, anthracite colour, Gold hour-ring, circular-grained with polished bevelling, black treatment. Gold hour markers. Power-reserve and GMT in gold, hand matt lapped, Small second, circular-grained. Hands: Hours and minutes in polished gold, with Super-LumiNova. Small seconds in polished steel, black treatment. Power-reserve in polished steel, hand-polished countersink. 2nd time zone GMT indicator, red.