The Corum Classical Billionaire Tourbillon is an ultra-limited edition wristwatch with 850 diamonds. It is a manually wound skeletonized Caliber CO-372 by Corum and La Joux-Perret. The case is 46 mm in diameter. It comes in mutltiple versions ranging from $325,00 to $998,000. What makes it ultra-limited is the fact that there are only 10 pieces of each of the four variations.