Thanks to the new barrel architecture and the superior efficiency of the new Chronergy escapement, the new Day-Date provides remarkable power reserve that extends into three days. The newly introduced perpetual self-winding 3255 caliber with 14 patents, entirely developed and manufactured by Rolex, also sets new standards for precision, resistance to shock and magnetism, reliability and ease of use. Along with the new and more efficient Chronergy escapement, innovations include the more resilient blue Parachrom spring in the oscillator, as well as the new-generation Perpetual rotor for more rapid winding. The 40mm 18K white gold Oyster case with fluted bezel features scratch-resistant sapphire and Cyclops lens over the date window. With a screw-down case back and Twinlock double waterproofness system for the screw-down crown, it is water resistant to 100m. The watch is worn on the wrist with an 18K white gold President bracelet with semi-circular three-piece links and a concealed deployment Crownclasp. The silver dial with quadrant motif features centre hands for hours, minutes and seconds, as well as instantaneous day and date in apertures.