Audemars Piguet 26585XT.OO.1220XT.01 Royal Oak Perpetual Calendar Openworked 41 150th Anniversary Skeleton Dial Watch

Audemars Piguet Royal Oak Perpetual Calendar “150th Anniversary” – Ref. 26585XT.OO.1220XT.01

Introducing the Audemars Piguet Royal Oak Perpetual Calendar “150th Anniversary” (Ref. 26585XT.OO.1220XT.01), a limited-edition celebration of AP’s sesquicentennial. Case Shape: Octagonal. Released in 2025 and restricted to just 150 pieces worldwide, this striking 41 mm timepiece marks the swan song of the esteemed Calibre 5135 open‑worked perpetual calendar movement, beautifully set within a cutting-edge combination of titanium and Bulk Metallic Glass (BMG) for an avant-garde yet wearable aesthetic.

Case & Materials

• Case Size: 41 mm diameter × 9.9 mm thickness, offering a refined and contemporary Royal Oak profile.
• Materials: Titanium case middle and screw-locked crown ensure lightness and resilience, while a BMG bezel and caseback frame fuse modern material innovation with industrial-chic texture.
• Water Resistance: Rated to 20 m (2 bar), suitable for daily wear.

Dial & Display

Beneath its sapphire dial lies a skeletonized perpetual calendar, accented with blue counter surrounds, a coordinating inner bezel, and 18‑carat white‑gold hour markers. The signature “bathtub” hour and minute hands are filled with luminescent material, combining playfulness and functionality into an intricate but legible display.

Movement & Complication

• Calibre 5135: The automatic open‑worked perpetual calendar movement includes complete date, day, month, leap-year, week indication, and astronomical moon phase. It comprises 374 components, 38 jewels, and runs at 2.75 Hz (19,800 vph) with approximately 40 hours of autonomy.
• Legacy Mechanism: This reference represents the final Royal Oak to house the historic Calibre 5135—rather than newer 5136 or 7121 calibres—making it notably collectible as the end of a technical lineage.

Bracelet & Wearability

The integrated bracelet features titanium links studded with BMG elements, echoing the case’s blend of textures. Secured by a titanium AP folding clasp, the design offers exceptional lightness, tactile durability, and visual contrast—encapsulating modern elegance.

Visual & Collector Highlights

This model bridges a vintage-inspired look—drawing from past Royal Oak open-worked perpetual calendars—with futuristic materials. Its skeletonized sapphire dial offers a glimpse into the complex perpetual calendar mechanism, while the contrast of blue accents against the metallic frame echoes avant-garde minimalism. Limited to 150 pieces, it’s a sought-after artifact in any serious collector’s trove.

Technical Summary

• Reference: 26585XT.OO.1220XT.01
• Case/Bracelet: Titanium with BMG, 41 mm × 9.9 mm, 20 m WR
• Dial: Sapphire skeleton with blue counters, white-gold hands and markers
• Movement: Calibre 5135 automatic perpetual calendar, 19,800 vph, 40 h PR, 374 parts, 38 jewels
• Complications: Perpetual calendar with week, moon-phase
• Edition: 150-piece “150th Anniversary” limited edition

Conclusion 26585XT.OO.1220XT.01

The Audemars Piguet Royal Oak Perpetual Calendar “150th Anniversary” Ref. 26585XT.OO.1220XT.01 embodies both technical refinement and material innovation. Marrying the final open‑worked Calibre 5135 with titanium and BMG, it celebrates AP’s heritage while charting a bold path into the future. For collectors desiring horological significance, exclusivity, and a narrative rooted in mastery and innovation, this model is an essential, statement-making masterpiece.