At 28 mm, the Oyster case is constructed in Yellow Rolesor, pairing Oystersteel with yellow gold throughout both the case and the three-piece solid-link Oyster bracelet. A domed bezel and scratch-resistant sapphire crystal with a Cyclops lens over the date complete the case, which features a screw-down crown with Twinlock double waterproofness and water resistance to 100 metres / 330 feet. The bracelet closes via a folding Oysterclasp fitted with an Easylink 5 mm comfort extension link.
The champagne-colour dial is set with diamonds mounted in 18 kt gold settings, lending warmth and sparkle to every glance at the time. Powering the watch is Rolex Caliber 2236, a perpetual, mechanical, self-winding movement with bidirectional winding via a Perpetual rotor and a power reserve of approximately 55 hours. The oscillator features a Syloxi hairspring in silicon with patented geometry and high-performance Paraflex shock absorbers, delivering a precision of -2/+2 seconds per day after casing.
Caliber 2236 carries Superlative Chronometer certification — reflecting both COSC testing and Rolex's own certification after casing — and offers centre hour, minute, and seconds hands alongside an instantaneous date with rapid setting and stop-seconds for precise time adjustment. Reference 279163-0012 is a study in the Lady-Datejust's enduring two-tone character.
