The Royal Oak transformed watchmaking when Gérald Genta designed it in 1972, establishing the luxury steel sports watch as a category and becoming Audemars Piguet's defining icon. Reference 15413OR represents the model at its most opulent and elusive — the "Rainbow" execution, in which the octagonal bezel is set with baguette-cut sapphires graduating through the full chromatic spectrum. Produced in 2019 in exceptionally limited numbers, with some accounts suggesting as few as ten examples, this rose gold configuration ranks among the rarest gem-set Royal Oaks ever made, prized by collectors for the convergence of Genta's enduring architecture with the maison's most ambitious high-jewelry artistry. The 41mm case in 18-karat rose gold measures 9.98mm thick, its signature octagonal bezel set with 32 baguette-cut rainbow-colored sapphires secured beneath the eight hexagonal screws. The fully diamond-paved rose gold-tone dial carries baguette-cut diamond hour markers and a date aperture at three. The self-winding Caliber 3120, visible through the sapphire caseback, delivers a 60-hour power reserve. An integrated 18-karat rose gold Royal Oak bracelet with AP folding clasp completes the watch. Reference Number: 15413OR.YY.1220OR.01 Model Family: Royal Oak Movement: Automatic Case Material: Rose Gold Bracelet Material: Rose Gold Dial: Diamond Paved Case Dimension: 41mm Year: 2021 Condition: Like New & Unworn Box & Papers: Original Box, Original Papers