Audemars Piguet Royal Oak Perpetual Calendar Openworked in Titanium & BMG – Hands-On Review
A New Era for the Royal Oak Perpetual Calendar
Audemars Piguet has signaled a clear generational shift with the introduction of the Royal Oak Selfwinding Perpetual Calendar Openworked powered by the new Calibre 7139. Released alongside a Code 11.59 counterpart, this Royal Oak version represents the most refined openworked perpetual calendar from the Le Brassus manufacture to date.
Case and Bracelet Design
At 41mm in diameter and just 9.5mm thick, the case impresses with its balance. This perpetual calendar feels slimmer and more wearable than earlier openworked Royal Oak QPs. The construction combines lightweight titanium with AP's proprietary Bulk Metallic Glass (BMG), used for the bezel, caseback frame, and bracelet studs.
The satin-brushed titanium contrasts with mirror-polished BMG flashes of a liquid-like glow. The integrated bracelet with BMG studs is light, fluid, and exceptionally well finished. The improved 50m water resistance reinforces that this is a perpetual calendar designed to be worn daily.
Technical Specifications
| Specification | Detail |
|---|---|
| Case Diameter | 41mm |
| Case Thickness | 9.5mm |
| Case Material | Titanium with BMG bezel |
| Dial | Sapphire openworked |
| Movement | Calibre 7139 (In-house) |
| Power Reserve | 55 hours |
| Water Resistance | 50m |
| Price | CHF 180,200 |
The Openworked Dial
The sapphire dial exposes Calibre 7139 while retaining good legibility. The layout follows a logical European order: day at 9 o'clock with 24-hour indicator, date at 12, month and leap year at 3, and moon phase at 6. Week numbers are printed on the inclined inner flange.
Calibre 7139: Crown-Only Adjustment
The coolest feature is the all-in-one crown system for all functions – no recessed correctors, no tools needed. The movement beats at 28,800 vibrations/hour and offers a 55-hour power reserve. Finishing is classic Audemars Piguet: hand-chamfered bridges with sharp internal angles, satin brushing, circular graining, and polished accents.
FAQ
Q: What is Bulk Metallic Glass (BMG)?
A: BMG is a palladium-based amorphous alloy used by AP for its mirror-like polish and high scratch resistance, providing a striking contrast to brushed titanium.
Q: How does the crown adjustment system work?
A: The all-in-one crown allows adjustment of all calendar functions without tools. Four positions control winding, calendar adjustment, time setting, and correction of day/week/moon phase.
Q: Is this a limited edition?
A: No, it is part of the permanent collection but production is highly limited and available exclusively through AP boutiques.
Source
Article based on hands-on review from Monochrome Watches (February 6, 2026).
Explore our Audemars Piguet Collection or learn about Perpetual Calendar Watches.