Royal Oak Selfwinding Perpetual Calendar Ultra-Thin

Audemars Piguet unveils a new variation of the Royal Oak Selfwinding Perpetual Calendar Ultra-Thin model.

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Royal Oak Selfwinding Perpetual Calendar Ultra-Thin

Le Brassus, February 2023 – Swiss Haute Horlogerie manufacturer Audemars Piguet is happy to unveil the new iteration of its 41 mm Royal Oak Selfwinding Perpetual Calendar Ultra-Thin model. This 200-piece limited edition is the heir to the RD#2 model launched in 2019, and to the developments that the Manufacture has been pursuing for several years in terms of ultra-thin calibres. Attired in titanium and featuring an entrancing new smoky-blue dial with three black counters, this new version combines aesthetic sophistication with a cutting-edge astronomical complication.

Royal Oak Selfwinding Perpetual Calendar Ultra-Thin
The new Royal Oak Selfwinding Perpetual Calendar Ultra-Thin, is based on Calibre 5133, a concentrated blend of watchmaking engineering powering a perpetual calendar movement measuring just 2.89 mm thick. © Courtesy of Audemars Piguet

New dial design

This new edition features titanium on the case, bracelet and bezel, while also incorporating the alternating finishes dear to Audemars Piguet. The screws and chamfers of the bezel, case and bracelet links are polished, while the other surfaces are adorned with a vertical satin-brushed finish. This aesthetic signature stems from a genuine symbiosis between the machine and the artisan’s hand: the former prepares the surfaces – those in titanium are particularly resistant – while the latter ensures all the final finishes ensuring perfect homogeneity.

This reference introduces a new smoky-blue dial developed especially for the model. Light in the centre and black around the rim, it is decorated with a sunburst motif endowing it with luminous aesthetics facilitating read-off of the calendar indications, month and leap year at 3 o’clock, date at 6 o’clock, day and day/night indicator at 9 o’clock.

Each of these items of information appears in a snailed black counter. The moon phase at 12 o’clock is the only indication whose design has not been modified. The dial remains punctuated by 12 luminescent applied hour-markers and two central hands, likewise luminescent.

On the caseback side, this new Royal Oak Selfwinding Perpetual Calendar Ultra-Thin features a sapphire crystal providing a chance to admire the technical prowess embodied in Calibre 5133.

Royal Oak Selfwinding Perpetual Calendar Ultra-Thin

5133, the benchmark Ultra-Thin Perpetual Calendar Calibre

Calibre 5133 was introduced in 2017 and pushed the limits of extra-thin complications into the realm of the ultra-thin. Elegantly combining robustness and reliability, it comprises 256 parts within a space measuring just 2.9 mm thick and 32 mm in diameter. This masterpiece of miniaturisation and engineering operates at a frequency of 2.75 Hz (19,800 vph) and delivers a power reserve of at least 40 hours.

Inside, the perpetual calendar functions usually placed on three separate levels are positioned on a single plane. This new technical feat led to the development of two patented innovations: the integration of the end-of-month cam with the date wheel and the association of the month cam with the month wheel. To further reduce thickness, the dial also acts as a bridge.

These major advances have been achieved through a combination of CNC (Computer Numerical Control) and CAD (Computer Aided Design) technologies used by the Manufacture since the 1980s.

Royal Oak Selfwinding Perpetual Calendar Ultra-Thin

The pursuit of cutting-edge developments

At its launch in 2018, the unique and soberly named “RD#2” became the world’s thinnest selfwinding perpetual calendar. In 2019, the commercial version of this prototype was launched and named Royal Oak Selfwinding Perpetual Calendar Ultra-Thin RD#2. Equipped with a movement measuring 2.9 mm thick (including the oscillating weight) housed in a case measuring just 6.2 mm thick, this reference is attired in a 950 titanium and platinum alloy combining state-of-the-art technology, aesthetic refinement and lightness.

Today, the Manufacture presents the worthy heir to this model, entirely made of titanium.

This new iteration also perpetuates the long tradition of calendar watches and ultra-thin movements at Audemars Piguet. A century ago, in 1921, the Manufacture began this two-fold quest with the thinnest pocket watch movement ever made (1.32 mm thick), followed by a similar record for a hand-wound wristwatch movement (1.64 mm in 1938) and then a selfwinding one (2.45 mm in 1967). In 1978, when the watch industry was entirely focused on the development of quartz watches, the Manufacture unveiled a selfwinding perpetual calendar wristwatch movement that was the thinnest in the world at the time of its launch (3.95 mm).

Today the new Royal Oak Selfwinding Perpetual Calendar Ultra-Thin represents the culmination of this age-old watchmaking approach, as well as a valuable stepping-stone towards future developments.

“Born in Le Brassus, raised around the world.”

Royal Oak Selfwinding Perpetual Calendar Ultra-Thin

Audemars Piguet Royal Oak Selfwinding Perpetual Calendar Ultra-Thin / 41 mm Technical specifications

Ref. 26586TI.OO.1240TI.01


  • Perpetual calendar with day, date, month, astronomical moon, leap year and day/night indications, hours and minutes.


  • Satin-brushed titanium case, glare-proofed sapphire crystal and caseback, titanium screw-lock crown, water-resistant to 20 m.
  • Box thickness: 6.2 mm


  • Smoky-blue dial with sunburst pattern, black counters, applied hour-markers and Royal Oak hands in white gold with luminescent coating.


  • Satin-brushed titanium bracelet with titanium AP folding clasp.
Ultra-Thin Perpetual Calendar Calibre 5133
Ultra-Thin Perpetual Calendar Calibre 5133

Movement specifications

  • Selfwinding Calibre 5133
  • Total diameter                                      32 mm (14 ¼ lignes)                                                    
  • Total thickness                                     2.9 mm                                   
  • Number of parts                                  256                                         
  • Number of jewels                                 37                                                                              
  • Minimum power reserve guaranteed   40 h                            
  • Frequency of balance wheel                  2.75 Hz (19,800 vibrations/hour)

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