The Audemars Piguet Royal Oak Perpetual Calendar Openworked (Ref. 26585CE.OO.1225CE.01) is a masterpiece of technical mastery, featuring a skeletonized sapphire dial that showcases the intricate movement components. The 41mm black ceramic case and bracelet exude a modern aesthetic, while the titanium clasp ensures durability and comfort. Powered by the self-winding Caliber 5135, this timepiece offers a 40-hour power reserve and displays a perpetual calendar with week indication, day, date, astronomical moon, month, and leap year. Water-resistant up to 20 meters, it combines functionality with elegance, making it a coveted choice for discerning watch enthusiasts.