| Bezel | Fluted |
| Bracelet | President, semi-circular three-piece links |
| Bracelet Material | 18 ct yellow gold |
| Calibre | 2236, Manufacture Rolex |
| Certification | Superlative Chronometer (COSC + Rolex certification after casing) |
| Clasp | Concealed folding Crownclasp |
| CollectionName | Datejust |
| Crystal | Scratch-resistant sapphire, Cyclops lens over the date |
| Dial | Dark grey set with diamonds |
| Diameter | 31 mm |
| Gem setting | Large VI set with 11 diamonds |
| Material | 18 ct yellow gold |
| Model Case | Oyster, 31 mm, yellow gold |
| Movement | Perpetual, mechanical, self-winding |
| Power Reserve | Approximately 55 hours |
| Reference / Code | 278278 |
| Water Resistance | Waterproof to 100 metres / 330 feet |
| Winding Crown | Screw-down, Twinlock double waterproofness system |
Dark Grey Dial
This dial features a large VI set with 11 diamonds. The sunray finish creates delicate light reflections on many dials in the Oyster Perpetual collection. It is obtained using masterful brushing techniques that create grooves running outwards from the centre of the dial. Light is diffused consistently along each engraving, creating a characteristic subtle glow that moves depending on the position of the wrist. Once the sunray finish has been completed, the dial colour is applied using Physical Vapour Deposition or electroplating. A light coat of varnish gives the dial its final look.
Fluted bezel
The Rolex fluted bezel is a mark of distinction. Originally, the fluting of the Oyster bezel had a functional purpose: it served to screw the bezel onto the case helping to ensure the waterproofness of the watch. It was therefore identical to the fluting on the case back, which was also screwed onto the case for waterproofness, using specific Rolex tools. Over time, the fluting became an aesthetic element, a genuine Rolex signature feature. Today the fluted bezel is a mark of distinction, in gold on this Datejust 31.
