The Audemars Piguet Royal Oak Double Balance Wheel Openworked 15407ST.OO.1220ST.02 is a technical showpiece that pairs a fully skeletonized 41mm stainless steel case with a warm pink gold-toned openworked movement for a striking two-tone aesthetic. The openworked design lays the mechanism bare, framed by a matching pink gold-toned inner bezel, with white gold applied hour markers and Royal Oak hands finished in luminescent coating for legibility. This reference marks the first time Audemars Piguet crafted the signature hexagonal bezel screws in pink gold rather than white gold on a steel Royal Oak, a detail that ties the whole two-tone theme together. Driving it is the in-house self-winding Calibre 3132, built around AP's patented double balance wheel system that mounts two balance wheels and hairsprings on a single axis to improve stability and precision. Composed of 245 parts and 38 jewels, the movement beats at 3 Hz with a 45-hour power reserve and is admired through both the openworked dial and the glareproofed sapphire caseback. At a slim 9.9mm thick and rated to 50 meters of water resistance, it wears comfortably as a sports watch while showcasing serious haute horlogerie craft. For the collector chasing the Royal Oak silhouette with a rare pink gold-toned twist, the 15407ST.02 is technical brilliance and iconic design in one.