Basel: Greubel Forsey’s Four Tourbillon

This is made possible by the asynchronous position of each of the four tourbillons, which are connected to two autonomous regulating organs. These organs, each housed in a tourbillon cage, and are coupled to the spherical differential which ensures transmission to the display system.

The movement is a patented hand-wound caliber, comprising 531 components, with 63 jewels, beating at 21,600 bph and with a power reserve of 50 hours. The two interior tourbillons at a 30° angle rotate every 60 seconds, the two exterior tourbillons rotate every 4 minutes.

The case, in 18kt rose gold, measures 43.5mm. It features an asymmetrical convex sapphire crystal and display back (with a lateral window done in a shaped sapphire crystal). It is water resistant to 30 meters. The dial is solid 18kt gold which has been blackened. The strap is alligator.