The Greubel Forsey Quadruple Tourbillon Secret is a timepiece unlike any other. This timepiece is a perfect example of how traditional horology can be pushed to its limits and innovation becomes the name of the game. The Quadruple Tourbillon Secret a.k.a Quadruple Tourbillon à Différentiel is a blend of art and technical innovation that encapsulates the very soul of its two creators with its fascinating four tourbillons. This watch is fitted with an asymmetrical case in 18K red gold —also available in platinum— measuring 43.50mm in diameter and 16.11mm in thickness. This fascinating timepiece is fitted with a lateral window on the case band at 8 o'clock that allows for full view of one of the double tourbillon cages. The alternating satin brushed and polished areas on the case create the perfect symphony that houses such a magnificent complication and a gorgeous black dial.

The black dial with gold 'appliqués' features a 50-hour power reserve indicator with running seconds at 2 o'clock, a 4-minute tourbillon rotation indicator at 5 o'clock and a 240-seconds register at 8 o'clock. The 240-seconds indicator is delicately engraved with French words that perfectly describe the intrinsic attributes and qualities of this horological masterpiece: 'Savoir-Faire', 'Inventeurs Horlogers', 'Créativité', 'Technicité', 'Univers Original', 'Bienfacture d'Exception', 'Oeuvre Unique', 'Noblesse Esthétique', 'Inventeurs Horlogers', 'Créativité' and 'Technicité'.

Now, let's explain how this amazing timepiece works. The Greubel Forsey Quadruple Tourbillon is fitted with two double-tourbillons composed by an inner tourbillon —set at a 30 degree angle and that rotates once every minute— and an outer tourbillon that rotates once every four minutes. The four tourbillons are connected at the heart of two autonomous regulating organs, where each regulating organ is composed of a balance wheel oscillator placed in the cage of the tourbillon that is located at an angle of 30 degrees and that rotates once every minute. This mechanism rotates within the cage of a second tourbillon every four minutes. The two oscillators independently regulated inside the four tourbillons are coupled by a spherical differential which transmits their combined precision to the time display. Two barrels connected in series supply power through the spherical differential to the tourbillons.   

The beating heart of this magnificent piece of 'haute horlogerie' is the Greubel Forsey calibre GF03 composed of 531 parts, 2 double-tourbillon cages with 128 parts each, a spherical differential composed of 28 parts and 63 olived-domed jewels in gold chatons. When fully wound, the calibre provides a power reserve of 50 hours beating at a frequency of 21,600 vph. The calibre is of course fully visible via the display case back.  

This fascinating timepiece is fitted with a black hand-sewn alligator strap with double-folding clasp engraved with the Greubel Forsey logo. The strap is very supple, elegantly finished and quite comfortable. 

The Greubel Forsey Quadruple Tourbillon Secret is available in a limited number of eight pieces in 18K red gold and 8 pieces in platinum.  If you appreciate 'haute horlogerie' and you have the money to play in the game, this timepiece is one that will for sure be featured in horological history books, as one of the most fascinating complications ever created. 

Sticker Price $805,000 USD. For more info on Greubel Forsey click here.