THE OYSTER CASE,
SYMBOL OF WATERPROOFNESS
A paragon of robustness and elegance, the Oyster case of the Datejust 31 is guaranteed waterproof to a depth of 100 metres (330 feet). Its middle case is crafted from a solid block of particularly corrosion-resistant Oystersteel.
The case back, edged with fine fluting, is hermetically screwed down with a special tool that allows only Rolex watchmakers to access the movement. The winding crown, fitted with the Twinlock double waterproofness system, screws down securely against the case. The crystal is made of virtually scratchproof sapphire and is fitted with a Cyclops lens at 3 o’clock for easy reading of the date. The waterproof Oyster case provides optimum protection for the Datejust 31’s high-precision movement.