The 15450ST is the 37 mm steel Royal Oak with date, introduced in 2012 alongside the 41 mm 15400ST. It shares calibre 3120, with about 60 hours of power reserve and a 22 ct gold rotor, and the Grande Tapisserie pattern of the larger version, but is more compact and therefore suited to a slimmer wrist.
The design is the same as that of the larger Royal Oak: the octagonal bezel with eight hexagonal screws, the integrated bracelet with tapering links and the alternation of brushed and polished surfaces. The watch is water-resistant to 50 metres. Anyone looking for a Royal Oak that wears discreetly without compromising the design often chooses this size. It was made until 2022; its successor is the 15550ST with calibre 5900.
On a pre-owned example we look at the finishing, which matters as much on a smaller case as on the 41 mm: rounded edges and blurred transitions point to earlier polishing. We also check the certificate and set, the folding clasp and the date of the last service.