At 31 mm, this Datejust 31 carries a round monobloc middle case crafted in White Rolesor, blending Oystersteel with white gold. The domed bezel is set with diamonds, while a scratch-resistant sapphire crystal with a Cyclops lens over the date window sits above the white dial. A solid case back and screw-down winding crown with Twinlock double waterproofness system contribute to water resistance rated to 100 metres / 330 feet.
Power comes from the Calibre 2236, a perpetual mechanical self-winding movement manufactured by Rolex, rated to -2/+2 seconds per day after casing and COSC certified. The oscillator features a Syloxi hairspring in silicon with patented geometry and high-performance Paraflex shock absorbers, while bidirectional self-winding via a Perpetual rotor provides a power reserve of approximately 55 hours. Functions include centre hour, minute, and seconds hands, an instantaneous date with rapid setting, and stop-seconds for precise time setting.
The Oyster bracelet in Oystersteel secures with a folding Oysterclasp featuring an Easylink 5 mm comfort extension link, allowing for easy on-wrist adjustments. Reference 278344RBR-0011 represents the Datejust 31 in a configuration that balances diamond detail with the durability of Rolex's Oyster architecture.
