The GMT Quadruple Tourbillon is radical in all its aspects. First of all, by its construction. The Quadruple Tourbillon is Greubel Forsey’s second Fundamental Invention, The mission: to average out positional errors due to gravity in all situations, especially in stable wristwatch positions. To achieve this, the original tourbillon has been elevated to realise its full potential: inclined at 30°, doubled and then quadrupled. The result, two synchronised Double Tourbillon 30° mechanisms, where a first cage, inclined at 30° and rotating in one minute, is nested within a second horizontal cage, completing a full rotation in four minutes. A spherical differential transmits the average timing rate of the four tourbillon cages, improving the overall chronometric performance of all the regulating organs. With this exclusive limited edition in titanium with striking blue accents, Greubel Forsey offers an unexpected alternative to the precious metals that High-end watchmaking traditionally favours.