Rolex Datejust 31 mm

The Rolex Datejust 31, reference 278278-0040, measures 31 mm across in yellow gold. The case has a fluted bezel and holds a champagne-colour dial under a scratch-resistant sapphire crystal with a Cyclops lens over the date. Inside is calibre 2236, a self-winding mechanical movement with a power reserve of approximately 55 hours, and Rolex certifies the watch as a chronometer. The dial carries a central seconds hand and an instantaneous date display, and the screw-down crown is part of the Oyster case construction. This is a women's dress watch built on the President bracelet, also in yellow gold, closed with a concealed folding Crownclasp. Water resistance reaches 100 metres, a figure the screw-down crown helps maintain.