Tourbillon 24 Vision Seconds This particular timepiece debuted at Geneva’s SIHH this year. Its simplicity-meets-aesthetics approach neatly showcases the concerns of its creators who have designed a case that is the embodiment of classic elegance. It is also the thinnest watch Greubel Forsey has created to date, with a mere thickness of 13.65mm. That figure increases to 16,025mm, however, because of the domed sapphire crystal caseback that reveals the tourbillon. The watch movement offers 72 hours of power reserve. Limited to 22 pieces.