The Royal Oak came to be referred to as the "first luxury sports watch” because steel, essentially known for its sturdiness, suddenly appeared in a particularly refined interpretation. It was also used in a sophisticated construction that was difficult to achieve, given the available machining methods and the hardness of the metal. The result was complemented by resolutely top-grade polished and brushed finishes. In terms of design, the model boasted bold and powerful features that were well equipped to stand the test of time. The deliberately angular lines were immediately noticeable, in particular the octagonal bezel and its hexagonal screws, which were always made of gold, not to mention the visible sealing joint serving to highlight the technical nature of the model. One originality of the case was that it had no lugs but rather a bracelet whose trapezoidal links were arranged in descending order for a tapered effect, and which seamlessly integrated the case to a degree rarely seen at the time. Meanwhile, the dial stood out with its tapisserie decoration composed of squares separated by channels.

In 2012 Audemars Piguet celebrated the 40th anniversary of the Royal Oak by launching a 39mm model that was almost identical to the original and which defines the current standard of the extra-thin line. The small differences lay in the updated style of the inscriptions and the blue background of the date disk which is colour-coordinated to the dial. Even the movement, which is still produced by the Manufacture, remained the same: Calibre 2121, a mechanical self-winding movement measuring 3.05mm thick and a benchmark in the field of ultra-thin movements. Slenderness doubtless played a role in the success of the first Royal Oak, effectively counterbalancing anything that might have been deemed excessive in the design and preserving the elegance expected from a luxury watch.

For the 50th anniversary of this legend in 2022, Audemars Piguet released a new generation of the original Royal Oak “Jumbo” Extra-Thin in a 39mm size. Cased in steel, yellow gold, rose gold or platinum, it uses the hours-minutes-date Calibre 7121 movement which incorporates an aerodynamic balance wheel. Slightly thicker than its predecessor at 3.2mm, this new movement stores more energy and is wound in both directions by the “50 Years” rotor. An Openworked version, also in celebration of the 50th anniversary, is powered by Calibre 7124 with renditions in steel and rose gold.