A CHRONOGRAPH MADE FOR THE ROAD

The Cosmograph Daytona was designed to be the ultimate timing tool for racing drivers thanks to its precision and its reliability. The watch, which is equipped with an additional mechanism to measure intervals of time displayed by secondary hands, also offers outstanding legibility of its functions. Time intervals can be measured to within one-eighth of a second with the centre chronograph seconds hand, while the two counters on the dial at 3 and 9 o’clock display elapsed time in minutes and hours respectively.

MEASURING SPEED UP TO 400 UNITS PER HOUR

The Cosmograph Daytona’s bezel, in gold or high-tech ceramic, functions as a tachymeter: its scale can be used to read an average speed over a given distance based on elapsed time. This scale, which offers optimal legibility, makes this watch the ideal instrument for measuring speeds up to 400 units per hour, expressed in kilometres, miles, or any other unit of measure.

THE COSMOGRAPH DAYTONA, SUPERLATIVE CHRONOMETER CERTIFIED

Like all Rolex watches, the Cosmograph Daytona is covered by the Superlative Chronometer certification redefined by Rolex in 2015. This exclusive designation attests that every watch leaving the brand’s workshops has successfully undergone a series of tests conducted by Rolex in its own laboratories and according to its own criteria. These certification tests apply to the fully assembled watch, after casing the movement, guaranteeing superlative performance on the wrist in terms of precision, power reserve, waterproofness and self-winding. The Superlative Chronometer status is symbolized by the green seal that comes with every Rolex watch and is coupled with an international five-year guarantee.

The precision of every movement – officially certified as a chronometer by the Swiss Official Chronometer Testing Institute (COSC) – is tested a second time by Rolex after being cased, to ensure that it meets criteria that are far stricter than those of the official certification. The precision of a Rolex Superlative Chronometer is of the order of −2/+2 seconds per day – the rate deviation tolerated by the brand for a finished watch is significantly smaller than that accepted by COSC for official certification of the movement alone.

The Superlative Chronometer certification testing is carried out after casing using state-of-the-art equipment specially developed by Rolex and according to an exclusive protocol that simulates the conditions in which a watch is actually worn and more closely represents real-life experience. The entirely automated series of tests also checks the waterproofness, the self-winding capacity and the power reserve of 100 per cent of Rolex watches. These tests systematically complement the qualification testing during development and production, in order to ensure the watches’ reliability, robustness, and resistance to strong magnetic fields and to shocks.

THE OYSTER CASE, SYMBOL OF WATERPROOFNESS

The Cosmograph Daytona’s Oyster case, 40 mm in diameter and guaranteed waterproof to a depth of 100 metres (330 feet), is a paragon of robustness and reliability. The middle case is crafted from a solid block of Oystersteel, 18 ct gold or 950 platinum. The case back, edged with fine fluting, is hermetically screwed down with a special tool that grants only certified Rolex watchmakers access to the movement. The Triplock winding crown, fitted with a triple waterproofness system and protected by an integral crown guard, screws down securely against the case, as do the chronograph pushers. The crystal is made of virtually scratchproof sapphire and benefits from an anti-reflective coating. The waterproof Oyster case provides optimal protection for the movement it houses.

Since 2023, the Cosmograph Daytona in 950 platinum has featured a transparent case back in sapphire crystal with an anti-reflective coating, offering the opportunity to admire the decorations on the movement and the pivoting of the oscillating weight.

CALIBRE 4131

The Cosmograph Daytona is equipped with calibre 4131, a self-winding mechanical chronograph movement entirely developed and manufactured by Rolex. A consummate demonstration of technology, this movement offers outstanding performance, particularly in terms of precision, power reserve, convenience and reliability. It incorporates a chronograph function with a reduced number of components, thereby further enhancing the movement’s reliability. The chronograph is engaged by a mechanism with a column wheel and vertical clutch. This enables an instantaneous and extremely precise start to the timing. Calibre 4131 is an evolution of calibre 4130, with which the Cosmograph Daytona was fitted between 2000 and 2022.

Calibre 4131 incorporates the patented Chronergy escapement, made of nickel-phosphorus, which combines high energy efficiency with great dependability and is also resistant to strong magnetic fields.

The movement is fitted with the blue Parachrom hairspring, manufactured by Rolex in a paramagnetic alloy. In addition to resisting strong magnetic fields, this hairspring offers great stability in the face of temperature variations as well as high resistance to shocks. It is equipped with a Rolex overcoil, ensuring the calibre’s regularity in any position.

The oscillator of calibre 4131 has a large balance wheel with variable inertia regulated extremely precisely via gold Microstella nuts. It is held firmly in place by a height-adjustable traversing bridge enabling very stable positioning to increase shock resistance. The oscillator is also mounted on the Rolex-designed, patented high-performance Paraflex shock absorbers, further enhancing the movement’s shock resistance.

Calibre 4131 is equipped with a self-winding system via a Perpetual rotor, which ensures continuous winding of the mainspring by harnessing the movements of the wrist to provide constant energy. Its oscillating weight, which is cut out and fitted with an optimized ball bearing, is made of yellow gold on the Cosmograph Daytona in 950 platinum. Thanks to its barrel architecture and the escapement’s superior efficiency, the power reserve of this movement extends to approximately 72 hours.

The Cosmograph Daytona’s movement will be seen only by certified Rolex watchmakers, yet it is beautifully finished and decorated. In particular, its bridges are embellished with Rolex Côtes de Genève, an exclusive decoration that differs from the traditional Côtes de Genève by the addition of a slight polished groove between each band. Calibre 4131 is also marked with the words ‘Chronometer Perpetual’ and ‘Superlative Adjusted’ engraved respectively on the oscillating weight and on the bridges. On the 950 platinum versions of the Cosmograph Daytona, it is visible to the wearer through the transparent case back.

BRACELET AND CLASP: SECURE AND COMFORTABLE

The Cosmograph Daytona is fitted with either a three-piece link Oyster bracelet or an Oysterflex bracelet, composed of two flexible, curved metal blades – one for each bracelet section – overmoulded with high-performance black elastomer. Both bracelets are equipped with a Rolex-designed, patented Oysterlock safety clasp that prevents accidental opening.

The Cosmograph Daytona’s Oyster bracelet is fitted with the Easylink comfort extension link, developed by Rolex, which allows the wearer to easily increase its length by approximately 5 mm, for additional comfort in any circumstance. On the versions in 18 ct gold or 950 platinum, the Oyster bracelet includes ceramic inserts – designed by the brand and patented – inside the links to enhance its flexibility and longevity.

The patented Oysterflex bracelet, developed by Rolex, is furnished with the Rolex Glidelock extension system, also developed by the brand and patented. On the Oysterflex bracelet, this inventive toothed mechanism has six notches of approximately 2.5 mm, allowing the bracelet length to be effortlessly adjusted up to some 15 mm.