Rolex Explorer II Oyster Perpetual — White Dial | Ref. 216570

The Explorer II, reference 216570, occupies a singular position in Rolex's professional catalogue as an instrument conceived for explorers navigating environments where the boundary between day and night is absent or ambiguous — polar expeditions, underground cave systems, and continuous-daylight Arctic environments being the archetypes for which the watch was developed. The 42mm Oyster case in Oystersteel — a proprietary 904L stainless steel alloy prized for its superior corrosion resistance — wears with the robust authority befitting a professional tool watch, with a unidirectional fixed bezel calibrated with a 24-hour scale for simultaneous tracking of two time zones.

The white dial carries a bold, immediately legible layout: large Mercedes-style hour hand, elongated minute hand, and the distinctive orange 24-hour hand that sweeps around the dial once every 24 hours rather than the conventional 12. Luminescent Chromalight material fills both the indices and hands, emitting a long-lasting blue glow in darkness — a practical improvement over the traditional LumiNova formulation that has been integral to Rolex's professional collection since 2008. The date window at three o'clock, as always magnified by the Cyclops lens, provides an additional temporal reference.

The movement is the manufacture Calibre 3187, a self-winding mechanical calibre with an independently adjustable 12-hour hand — distinct from the 24-hour hand — enabling home-time tracking without disrupting the local time display. A Paraflex shock absorber system provides superior impact resistance for field use. Operating at 28,800 vibrations per hour with approximately 48 hours of power reserve, the 3187 is certified as a Superlative Chronometer. The Oyster bracelet with flat three-piece links, flat-link centre, and Oysterlock safety clasp with Easylink comfort extension is water-resistant to 100 metres.