Rolex Datejust 31 31 mm 278240BBDC Steel Blue Rolex Datejust 31 31 mm 278240BBDC Steel…

The Rolex Datejust is one of the most enduring icons in watchmaking, introduced in 1945 as the first self-winding wristwatch to display the date in a window at 3 o'clock—a feature so influential that it became the defining reference point for the category. Over the decades, the Datejust has evolved into a broad family offered in multiple case sizes, and the 31mm configuration has emerged as the definitive choice for those who seek a refined, versatile silhouette that sits elegantly on a range of wrist sizes. Reference 278240BBDC represents a fully Rolex-produced expression of this legacy, bringing together the classic architecture of the Datejust with a suite of luxurious finishes.

The case measures 31mm across in Rolex's proprietary Oystersteel, a 904L stainless steel alloy chosen for its exceptional corrosion resistance and ability to take a mirror polish that retains its luster over years of wear. The Oyster case is a hallmark of Rolex engineering—hermetically sealed, robustly built, and water resistant to 100 meters (330 feet), making it equally at home on a formal evening out as it is during everyday activity. The crown screws down securely against the case, protecting the movement from moisture and dust.

At the heart of the dial experience is the bright blue lacquer surface set with Roman numeral hour markers, a configuration that balances classical horology with a bold, contemporary color sensibility. Blue dials have become among the most coveted in the Datejust lineup, and the Roman numeral layout amplifies the watch's old-world elegance, referencing centuries of European timekeeping tradition. The result is a dial that is simultaneously striking and deeply legible.

The bezel of the 278240BBDC is set with round diamonds, adding a continuous ring of brilliance that frames the blue dial with a jeweler's precision. Rolex's in-house gem-setting expertise ensures each stone is individually selected for cut, clarity, and color before being set by hand, yielding a uniform sparkle that catches light from every angle. Paired with the five-link Jubilee bracelet—one of Rolex's most celebrated and comfortable bracelet designs, first introduced alongside the original Datejust in 1945—the overall package is one of refined, wearable luxury.

The watch is powered by an automatic movement, providing the convenience of self-winding operation through the natural motion of the wrist. Rolex automatic calibers are manufactured entirely in-house and are celebrated within the industry for their precision, durability, and long service intervals, making this Datejust 31 a timepiece built not just to impress but to last across generations.

At Bizak & Co., we specialize in curating exceptional pre-owned and unworn Rolex timepieces for discerning buyers across the United States. The Rolex Datejust 31 reference 278240BBDC—with its diamond bezel, vivid blue Roman dial, and Jubilee bracelet in Oystersteel—is a rare and desirable configuration. Whether you are adding to a collection or seeking a signature everyday piece, we invite you to reach out to our team at bizakandco.com to confirm availability, ask questions, or purchase this watch online with confidence. Please note that Bizak & Co. is not an authorized Rolex dealer.