A vision for gearheads, the Harry Winston Opus X (www.harrywinston.com) is the 10th and latest timepiece in the Opus series, an annual collaboration between the American jeweler and an independent watchmaker. The $208,800 watch, which Harry Winston debuted in March, tells time using a cascading system of satellite gears that drive revolving hour, minute, and second indicators. The trio of gears itself describes one full rotation a day, a process that tracks the hour of an additional time zone (indicated with a wide yellow triangle). After toying with the aesthetics of the display, Harry Winston and Jean-François Mojon—the Swiss watchmaker who collaborated on the Opus X—slightly canted the wheels within the system of planetary gears, enabling it to orbit seamlessly underneath the domed crystal. The Opus X is limited to 100 pieces.