Rolex revisits its Oyster Perpetual Air-King watch, which was first launched back in the 1950s - the Air-King being a symbol of the brand’s aeronautical heritage. The new version comes in a 40mm steel case and features a distinctive black dial, which combines large 3, 6 and 9 Arabic numerals in white gold for the hours, with a prominent white minutes scale for navigational time readings. Crafted from a solid black of corrosion-resistant steel, the Oyster case is a paragon of robustness and water-resistant to depths of 100 metres. In addition to the solidity of the case, the Air-King’s movement is shielded against magnetic fields, just like pilots’ watches of the past. The watch keeps time with Rolex calibre 3131 - an automatic mechanical movement with a Parachrom hairspring - which is insensitive to magnetic fields and offers great stability in the face of temperature variations and shocks. In 2015, Rolex redefined its precision requirements and has awarded this watch the Superlative Chronometer certification, which ensures a daily variation of just -2/+2 seconds, more than twice that required of an official chronometer.