Housed in a round 31 mm Oystersteel case, the Datejust 31 reference 278240-0003 is built around the classic Oyster architecture: a monobloc middle case, screw-down case back, and a screw-down Twinlock winding crown that together deliver water resistance to 100 metres / 330 feet. Scratch-resistant sapphire crystal with a Cyclops lens magnifies the date, while the domed bezel keeps the profile clean and timeless.
The white dial features Roman numeral hour markers and houses the Calibre 2236 — a perpetual, mechanical, self-winding movement manufactured by Rolex rated to a precision of -2/+2 seconds per day after casing, qualifying it as a Superlative Chronometer (COSC certified, then further certified by Rolex post-casing). A Syloxi silicon hairspring with patented geometry works alongside Paraflex shock absorbers, and bidirectional winding via the 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 adjustment.
The watch rides on an Oystersteel Oyster bracelet composed of three-piece solid links and secured by a folding Oysterclasp fitted with an Easylink 5 mm comfort extension link, allowing easy on-the-fly sizing adjustments.
