You know when you hit the sweet spot. It can be out on the fairway, in the batter's box, or, after a long night of celebrating the Fourth of July, that one cool spot on the underside of your pillow. In the watch world, Piaget hit that spot between masculine and delicate with their Altiplano 38mm Skeleton. Created specifically for ONLY WATCH 2013 - the 5th installment of the biennial charity auction for Duchenne muscular dystrophy - the Altiplano is the world's thinnest automatic openworked watch, running a simply elegant movement measuring just 2.40mm thick with a case finished in a black PVD to add a beautiful contrast to the internal white gold. In addition to this piece from Piaget, 32 other prestigious brands will be contributing unique or first-in-a-series watches at the event held in Monaco. The Only Watch auction will be preceded by a traveling exhibition of the full collection, which is making stops in Singapore, Hong Kong, Beijing, New York, and Geneva before completing the journey at the Monaco Yacht Show on September 28. If you don't have the credentials to find your way into an event of this magnitude, continue after the click like the rest of us.