The Audemars Piguet Royal Oak Selfwinding Chronograph "50th Anniversary" Steel Blue Dial 41mm Ref. 26240ST.OO.1320ST.01 blends technical performance with signature Royal Oak design. This 41mm stainless steel chronograph features a “Grande Tapisserie” dial in the iconic Bleu Nuit, Nuage 50 shade, with matching subdials and luminescent white gold hour markers. The case is 12.4mm thick and fitted with a glareproofed sapphire crystal and screw-locked crown, ensuring water resistance up to 50 meters. Powered by the in-house Caliber 4401 selfwinding movement, the watch offers a 70-hour power reserve and flyback chronograph functionality for precise timekeeping. The anniversary edition includes a dedicated “50-years” oscillating weight, visible through the exhibition caseback. Completing the look is a robust stainless steel bracelet with AP folding clasp. Key features include the flyback chronograph, anniversary rotor, and distinctive Royal Oak styling, making it a strong choice for collectors and enthusiasts alike.