The Audemars Piguet Royal Oak Perpetual Calendar Ref. 26597PT.OO.1220PT.01 is an ultra-rare and collectible masterpiece, limited to just 20 pieces and created as a special edition exclusively for the Japanese retailer Yoshida. Housed in a stunning 41mm case and integrated bracelet forged from 950 platinum, this timepiece features the iconic octagonal design with a glare-proofed sapphire crystal caseback revealing the intricate movement. The striking black dial is adorned with the signature “Grande Tapisserie” pattern, two-tone black and rhodium-toned counters, and white gold Royal Oak hands with luminescent coating for optimal legibility. At its heart beats the ultra-thin in-house automatic Caliber 5134 (just 4.32mm thick), a perpetual calendar movement with a 40-hour power reserve, visible through the sapphire caseback, that precisely indicates the day, date, month, moon phases, and leap year cycle, requiring just one correction every 122 years. With a slim 9.5mm profile and 20-meter water resistance, this 2019 release offers a stealthy yet luxurious way to wear a precious metal Royal Oak, appealing to the most discerning collectors who seek exclusivity, horological complexity, and understated prestige. Key specifications: 41mm 950 platinum case and bracelet; black “Grande Tapisserie” dial with perpetual calendar and moon phase; in-house Caliber 5134 automatic movement; 40-hour power reserve; 20m water resistance; limited edition of 20 pieces.