Audemars Piguet Royal Oak 15305ST, steel

In 2010, Audemars Piguet introduced the reference 15305 (in steel), at SIHH - featuring an open-worked version of AP’s in-house calibre 3120, seen in the ref. 15300. The slate-grey, ‘anthracite’ dial includes all the traditional indications of a time-only watch, with white-gold, applied hour-markers and Royal Oak hands (with luminescent coating).

The steel case and bracelet are excellently finished, with angular, beveled and polished edges - striking the perfect balance between utilitarian function and elegant design. The polished screws, bezel and case edges fantastically-contrast with the brushed surface of the case and bracelet. At 39mm in diameter, and only 9.4mm thick, this Royal Oak ref. 15305 case is a beautiful twist of perspectives and size, further demonstrating a more industrial feel over its traditional contemporaries. The outer-case back correctly displays the unique serial number, along with its sequential case number.

This Royal Oak ref. 15305 is powered by the AP caliber 3129, derived from Audemars Piguet’s in-house 3120 calibre movement. The automatic 3129 calibre features 38 working jewels, 239 individual components and ceramic ball bearings to support the full-diameter rotor, manufactured from 22-carat gold and embellished with Audemars Piguet’s monogram.

The glare-proofed sapphire display case-back allows for an uninterrupted view of the movement decoration, which exhibits prominent, polished bevels on the edges of the diamond-cut bridges, with ruthenium plating for its dark grey finish. The skeletonised movement is finished in contemporary style, forming geometric shapes in the open-working. The balance oscillates at a rate of 21,600 vibrations per hour, with a power reserve of 60 hours.

This example comes as a full-set, with its original box and stamped paperwork.

Viewings can be arranged in Central London by appointment.

Closer look

Brand:	Audemars Piguet
Model:	Royal Oak Ref. 15305ST.OO.1220ST.01
Movement:	mechanical automatic AP Calibre 3129
Functions:	hours, minutes, centre seconds
Features:	display back, open-worked, skeletonised
Case:	39mm stainless steel
Crystal:	sapphire front and back
Bracelet:	original steel bracelet and clasp
Year:	2015
Box & papers:	box and papers