Rolex Datejust 31 31 mm 278240BKRJ Steel Black

The Rolex Datejust is one of the most enduring and recognized watch designs in horological history, having defined the aesthetic of the classic dress sport watch since its introduction in 1945. Celebrated for being the first self-winding wristwatch to display the date in a window at 3 o'clock, the Datejust has evolved across decades while preserving its essential elegance and legibility. The 31mm format, reference 278240BKRJ, occupies a refined middle ground — larger than the traditionally feminine 28mm yet more discreet than the full 36mm, making it a versatile choice for a broad range of wearers who appreciate understatement and precision in equal measure.

The case of the 278240BKRJ is crafted entirely from Oystersteel, Rolex's proprietary 904L stainless steel alloy, which is valued for its exceptional corrosion resistance, lustrous polish retention, and superior hardness compared to more common 316L steel. The 31mm Oyster case is sealed to 100 meters (330 feet) of water resistance, anchored by Rolex's Twinlock screw-down crown system, ensuring robust protection against the elements whether the watch is worn at the office or poolside.

The black dial on reference 278240BKRJ delivers the kind of bold, high-contrast legibility that has made dark-dialed Datejusts perennially in demand. Against the polished indices and hands, the black surface creates a classic and contemporary aesthetic simultaneously — dressed up under a cuff or worn casually, it reads with effortless authority. The stainless steel domed bezel frames the dial with characteristic Rolex restraint, avoiding distraction and keeping the focus precisely where it belongs.

The Jubilee bracelet is, for many collectors and enthusiasts, the definitive Datejust bracelet. Introduced alongside the Datejust itself in 1945, its five-piece link construction creates a supple, finely articulated drape on the wrist that is immediately recognizable and deeply comfortable for all-day wear. On reference 278240BKRJ, the Jubilee is rendered in Oystersteel, finished with a combination of polished center links and brushed outer links that play beautifully against both the dial and the case. The Crownclasp folding safety clasp ensures a secure fit and easy adjustment.

This Rolex Datejust 31 reference 278240BKRJ is certified authentic and offered in brand-new condition at Bizak & Co. As a trusted luxury watch dealer, Bizak & Co. sources genuine Rolex timepieces and stands behind every sale with expert knowledge and dedicated customer service. Whether you are buying your first Rolex or adding a cornerstone piece to a growing collection, this black-dial Datejust 31 is a compelling, timeless choice available for purchase online now at bizakandco.com.