Rolex Datejust 31 31 mm 278240GRO Steel Dark Grey

The Rolex Datejust is the definitive Swiss dress watch, introduced in 1945 as the first self-winding wristwatch to display the date in a window at 3 o'clock — a then-revolutionary complication. The 31 mm case size occupies a refined middle ground in the Datejust family, large enough to make a confident statement yet proportioned to suit a wide range of wrists with elegance rather than ostentation. Reference 278240GRO is one of the most versatile expressions in the current Datejust 31 lineup, pairing the timeless architecture of the Oyster case with a color story that feels modern and understated.

The case and bracelet of the 278240GRO are crafted entirely in Rolex's 904L Oystersteel, an alloy renowned in the industry for its superior corrosion resistance, brilliant polish retention, and exceptional hardness. The 31 mm Oyster case is secured by a screw-down Triplock crown, giving it the structural integrity the Oyster family is famous for. The domed bezel in matching Oystersteel frames the dial with clean, classic lines that have defined the Datejust silhouette for decades.

The dial is the heart of this reference. The dark grey finish delivers a cool, sophisticated tone that shifts subtly in different lighting — appearing almost charcoal under direct light and deepening to a rich slate in shadow. Roman numeral hour markers cut through the surface with confident legibility, lending the watch a distinctly classical character that sets it apart from index-dial Datejust references. The combination of dark grey and Roman numerals is a pairing that reads as jewelry-grade refinement while remaining entirely wearable across business and formal settings.

Power comes from a Rolex automatic movement, the hallmark of a caliber family developed, manufactured, and regulated entirely in-house in Geneva. Rolex movements are assembled and tested to exceed COSC chronometer standards and are known for their reliability over decades of continuous use. The movement is housed within the hermetically sealed Oyster case, providing robust protection for the mechanism inside.

The Datejust 31 in Oystersteel on an Oyster bracelet is one of the most practical luxury watches ever made — the three-link Oyster bracelet with its Oysterclasp is secure, comfortable, and resizes easily to fit virtually any wrist. Whether you are wearing the 278240GRO as a daily companion or reserving it for dressed occasions, its proportions and dark grey Roman dial make it equally at home with a suit or smart-casual attire.

At Bizak & Co., we specialize in curating pre-owned and current Rolex references that represent genuine value and lasting desirability. The 278240GRO is a reference that holds strong appeal in the secondary market precisely because the dark grey Roman dial configuration is a perennially sought-after variant. Browse our listing or contact our team directly to ask about the current condition, documentation, and pricing for this Rolex Datejust 31 — we are here to help you buy with confidence.