Datejust 31 – M278240-0005

Reference

Model case

Bezel

Water-resistance

Movement

Calibre

Power reserve

Bracelet

Dial

Certification

Superlative Chronometer (COSC + Rolex certification after casing)

Silver dial

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.

Oystersteel

Rolex uses Oystersteel for its steel watch cases. Specially developed by the brand,
Oystersteel belongs to the 904L steel family, alloys most commonly used in high-
technology and in the aerospace and chemical industries, where maximum
resistance to corrosion is essential. Oystersteel is extremely resistant, offers an
exceptional finish once polished and maintains its beauty even in the harshest
environments.

The Oyster bracelet

The Oyster bracelet is a perfect alchemy of form and function, aesthetics and technology,
designed to be both robust and comfortable. It is equipped with an Oysterclasp and
the Easylink comfort extension link, also exclusive to Rolex. This ingenious system
allows the wearer to increase the bracelet length by approximately 5 mm, providing
additional comfort in any circumstance.