Reference 228348RBR-0037 presents the Day-Date 40 in an 18 kt yellow gold Oyster case measuring 40 mm, built around a monobloc middle case with a screw-down case back and screw-down winding crown secured by the Twinlock double waterproofness system. The bezel is set with diamonds, and a scratch-resistant sapphire crystal with a Cyclops lens over the date completes the case. Water resistance extends to 100 metres / 330 feet.
The dial is diamond-paved throughout, with 10 baguette-cut diamonds serving as hour indicators. Day and date displays appear in separate apertures with secure rapid-setting, and a stop-seconds function allows for precise time setting. The 18 kt yellow gold President bracelet — defined by its semi-circular three-piece links — fastens with a concealed folding Crownclasp.
Power comes from the Calibre 3255 perpetual, mechanical, self-winding movement, a Manufacture Rolex calibre offering a precision standard of -2/+2 seconds per day after casing and a power reserve of approximately 70 hours. The oscillator features a paramagnetic blue Parachrom hairspring and high-performance Paraflex shock absorbers. The watch carries Superlative Chronometer certification, reflecting both COSC testing and Rolex certification after casing.
