Audemars Piguet 15551ST Royal Oak 50th Anniversary SS Diamond Bezel Grey Dial

Celebrating the Royal Oak’s 50th anniversary, the reference 15551ST.ZZ.1356ST.03 is a striking 37 mm stainless steel time‑and‑date model distinguished by its diamond‑set bezel and sophisticated grey “Grande Tapisserie” dial. Introduced in 2022 as part of AP’s design evolution, it houses the new Calibre 5900 automatic movement—an ultra‑thin 3.9 mm caliber beating at 4 Hz with a 60‑hour power reserve and a dedicated “50‑years” oscillating weight visible through the sapphire caseback. The 40 brilliant‑cut diamonds (~0.92 ct) framing the bezel lend a refined, celebratory touch, while the integrated steel bracelet maintains the Royal Oak’s iconic aesthetic. With a modest 50 m water resistance, this piece emphasizes elegance over sportiness, making it a rare and elegant collector’s example of AP’s milestone celebration. Its combination of technical refinement, anniversary symbolism, and tasteful gem setting ensures it stands out in both historical significance and horological appeal. Unworn with Audemars Piguet box and digital warranty card.