Unveiled in 2015, it was introduced on the first model when it was launched the same year and on the second in 2019. This caliber incorporates the patented Chronergy escapement, which combines high energy efficiency with great operational safety. Made of nickel-phosphorus, this escapement resists high magnetic fields.
The movement also includes the blue Parachrom hairspring, produced by Rolex in a paramagnetic alloy. This hairspring also has great stability in the face of temperature variations as well as high shock resistance.
It is also equipped with a Rolex terminal curve, which ensures regularity of walking in all positions. The oscillator is mounted on high-performance Paraflex shock absorbers, developed by the brand and patented, which give the movement increased resistance to shocks.
As for the oscillating weight, it is equipped with a ball bearing optimized since 2023.
The caliber 3255 (COCS) is powered by an automatic winding system using a Perpetual rotor. Thanks to the architecture of its barrel and the superior efficiency of its escapement, it benefits from a power reserve of approximately 70 hours.
The Day-Date 40 and Day-Date 36 come with a President bracelet. Created especially for the Oyster Perpetual Day-Date and unveiled in 1956 at the launch of this watch, this three-link bracelet, made exclusively in 18 ct gold or 950 platinum, is still today reserved for the Day Date as well as to the Datejust in precious metal.
Equipped with an invisible Crownclasp with folding clasp, it incorporates, inside its links, ceramic inserts – designed by Rolex and patented – which improve its fluidity to wear and its longevity. These watches are guaranteed for five years.
