Rolex has introduced four new reference models in its female-focused Oyster Perpetual Datejust 31 reference model, featuring a “Rolesor” case that combines Oyster steel and 18k white gold, all with dials in a range of vibrant colorways. Here’s everything you need to know about Rolex’s new Oyster Perpetual Datejust 31 model.
The first timepiece features a bezel set with 46 brilliant-cut diamonds and a fuchsia sun-treated dial at 6 o’clock adorned with diamond-set Roman “VI” numerals. The remaining three watches feature fluted bezels in white gold, with mint green sun-polished dials, white lacquered dials, and dark grey sun-polished dials. The hands, hour markers, and Roman numerals of each watch are crafted in 18-karat white gold. 
The case of the new Datejust 31 is 31mm in diameter. According to Rolex, it is guaranteed to be water-resistant to a depth of 100 meters. The middle of the case is made from a single piece of Oystersteel, an alloy from the 904L steel family that is commonly used in the aerospace industry for its corrosion-resistant properties similar to those of precious metals. Protecting the case and dial is a scratch-resistant sapphire crystal, and a Cyclops lens is mounted on the date window at 3 o’clock. The screw-down case-back has subtle grooves on the edges, an element first introduced on the Oyster model in 1926, and is secured with a unique tool that allows only Rolex watchmakers to access the movement.
The new Datejust 31 is equipped with a movement developed and manufactured in-house by Rolex. Its patented geometry ensures the regularity of the movement in any position, compensating for gravitational errors caused by differences in the distance and thickness of the hairspring. The movement is fitted with a paramagnetic nickel-phosphorus escapement wheel, while the oscillator of the movement features a patented paramagnetic shock absorber designed by Rolex to help increase the resistance of the movement to shocks. It is also powered by an automatic winding module through the perpetual wheel, which provides approximately 55 hours of power.
The new Oyster Perpetual Datejust 31 meets Rolex’s Superlative Chronometer certification, redefined in 2015, which requires each fully assembled timepiece to undergo a series of tests, including testing the watch’s performance and precision on the wrist, power reserve, water-resistance and the movement’s ability to be self-winding. The Rolex Superlative Chronometer must meet the standard setting of -2/+2 seconds/day or more to be named the official “Superlative Chronometer”.
