The Audemars Piguet Royal Oak Selfwinding reference 15550ST.OO.1356ST.07 is a 37mm luxury sports watch featuring a stainless steel case and an integrated bracelet. This model is characterized by the collection’s signature octagonal bezel secured by eight hexagonal screws and a grey Grande Tapisserie dial. It has a slim profile with a thickness of approximately 9mm and is protected by a scratch-resistant sapphire crystal and caseback. The timepiece is powered by the self-winding calibre 5900, which operates at a frequency of 4Hz and offers a power reserve of 60 hours.
In terms of complications, the watch provides essential timekeeping functions including hours, minutes, and center seconds, along with a date aperture located at the 3 o’clock position. The dial features white gold applied hour-markers and Royal Oak hands with luminescent coating for enhanced legibility. The case is designed with a water resistance of 50 meters, making it suitable for everyday splashes but generally not recommended for swimming or high-impact water activities.
General reviews of the 15550ST highlight its versatile 37mm size, which is often described as a perfect unisex diameter that accommodates various wrist sizes more comfortably than the larger 41mm models. The updated design is praised for its refined ergonomics, particularly the thinner and more tapered bracelet. While the high level of hand-finished polishing and brushing is a major aesthetic draw, some owners note that the steel surfaces are prone to picking up visible scratches. The transition to the calibre 5900 is generally viewed as a positive technical upgrade, though some enthusiasts miss the brand’s older in-house movements.