Rolex Ladies Datejust Reference #: 278384RBR

The Rolex Datejust 31 reference 278384RBR features a 31 mm Oyster case constructed in White Rolesor, a proprietary combination of Oystersteel (904L steel) and 18k white gold.  The case architecture is monobloc with a screw-down case back and winding crown equipped with the Twinlock double waterproofness system. 

• Crystal: Scratch-resistant sapphire with a Cyclops lens over the date aperture. 

• Bezel: Set with 46 diamonds (approx.  1.02 carats total weight, varying slightly by specific dial configuration).

• Water Resistance: Waterproof to 100 meters (330 feet). 

All 278384RBR models are powered by the Calibre 2236, a perpetual, mechanical, self-winding movement manufactured entirely by Rolex.  It represents a significant technical advancement in Rolex's smaller caliber offerings.

• Power Reserve: Approximately 55 hours. 

• Frequency: 28,800 vibrations per hour (4 Hz). 

• Jewels: 31 jewels.

• Oscillator: Features a Syloxi hairspring made of silicon with patented geometry, offering exceptional stability against temperature fluctuations and magnetic fields. 

• Shock Resistance: Equipped with high-performance Paraflex shock absorbers to increase resistance to impacts. 

• Winding: Bidirectional self-winding via a Perpetual rotor. 

• Functions: Center hour, minute, and seconds hands; instantaneous date with rapid setting; stop-seconds for precise time setting.