Measuring 28 mm across, the round case is crafted in 18 kt yellow gold with a solid case back, a screw-down winding crown featuring the Twinlock double waterproofness system, and water resistance to 100 metres / 330 feet. A scratch-resistant sapphire crystal with a Cyclops lens over the date sits atop the champagne dial, which is fitted with stick hour markers.
Power comes from the Calibre 2236, a perpetual, mechanical, self-winding movement produced by Manufacture Rolex. It operates with a precision of -2/+2 seconds per day after casing, delivers a power reserve of approximately 55 hours via bidirectional self-winding through a Perpetual rotor, and features a Syloxi silicon hairspring with patented geometry alongside Paraflex shock absorbers. The movement carries Superlative Chronometer certification, combining COSC testing with Rolex's own post-casing verification.
Functions include centre hour, minute, and seconds hands, an instantaneous date with rapid setting, and stop-seconds for precise time setting. The 18 kt yellow gold President bracelet closes with a concealed folding Crownclasp, completing this reference as model Lady-Datejust 279178-0001.
