Greubel Forsey revealed in 2012 the double double-tourbillon called the Quadruple Tourbillon Secret. To house these Tourbillons, the size of the watch is big; thickness at over 16mm. And considering the 519 components and FOUR tourbillons that reside inside, with a diameter of 43.5mm, it’s all justified. Only 16 pieces will be made in total, 8 in platinum and 8 in 5N red gold. On my wrist is one of 8 Red Gold piece. Priced at US$815,000.00