Rolex Cosmograph Daytona M126503 Stee 1

Specifications

• Model: Rolex Cosmograph Daytona

• Reference Number: M126503

• Case Size: 40mm

• Case Material: Oystersteel and 18ct Yellow Gold (Rolesor)

• Bezel: Fixed Yellow Gold with Tachymeter Engraving

• Dial: White (Other Variants: Black, Champagne)

• Crystal: Scratch-Resistant Sapphire

• Caseback: Transparent Sapphire (New Feature)

• Movement: Rolex Caliber 4131 (In-House, Self-Winding Chronograph)

• Power Reserve: 72 Hours

• Functions: Chronograph, Hours, Minutes, Small Seconds, Tachymeter

• Bracelet: Oyster (Steel and Yellow Gold)

• Clasp: Oysterlock Safety Clasp with Easylink 5mm Extension

• Water Resistance: 100 meters / 330 feet

• Certification: Superlative Chronometer (COSC + Rolex Internal Tests)

The Rolex Cosmograph Daytona M126503 blends the technical excellence of a modern chronograph with the enduring elegance of two-tone construction. Introduced in 2023, this reference updates the iconic Daytona line with subtle refinements, luxurious materials, and the new-generation Caliber 4131 automatic movement. A combination of Oystersteel and 18ct yellow gold gives the M126503 its distinct “Rolesor” identity — the perfect mix of resilience and sophistication.

The 40mm Oyster case, with its classic round silhouette and clean lines, is crafted from corrosion-resistant 904L stainless steel and features polished yellow gold accents on the bezel, crown, and chronograph pushers. The fixed bezel in solid 18ct gold is engraved with a tachymetric scale, enabling precise measurement of average speeds — a feature synonymous with the Daytona’s motorsport heritage.

The dial of the M126503 is available in multiple configurations, but one of the most sought-after is the white lacquer dial with gold-ringed chronograph sub-dials at 3, 6, and 9 o’clock. This classic layout includes a 30-minute counter, 12-hour counter, and running seconds, allowing for practical time tracking with refined aesthetics. The hour markers and hands are crafted from yellow gold and filled with Chromalight for long-lasting luminescence in dark conditions.

Rolex’s proprietary Triplock crown system, combined with the solid screw-down caseback, ensures water resistance up to 100 meters (330 feet), making the Daytona not just beautiful, but dependable in a wide range of settings.

The heart of this timepiece is the new Caliber 4131, a Rolex-engineered chronograph movement that builds upon the legendary 4130. This in-house automatic caliber features a Chronergy escapement, Paraflex shock absorbers, and a skeletonized rotor, contributing to improved energy efficiency and long-term durability. The watch delivers a 72-hour power reserve, ensuring it stays accurate and functional even after days off the wrist.

The movement is regulated to Superlative Chronometer standards, offering accuracy of -2/+2 seconds per day after casing, exceeding COSC specifications. A major innovation in the M126503 is the transparent sapphire caseback, which lets collectors and enthusiasts admire the detailed finishing and advanced movement design — a first for Daytona two-tone models.

The Oyster bracelet, another Rolex hallmark, combines brushed Oystersteel outer links with polished yellow gold center links for a striking, dynamic contrast. Secured with an Oysterlock safety clasp, it also includes the Easylink comfort extension, allowing for a 5mm bracelet adjustment — ideal for subtle changes in wrist size or temperature-related expansion.

With its blend of sporty design, luxury materials, and mechanical innovation, the Rolex Daytona M126503 is a worthy successor in the Daytona lineage. Whether you’re a motorsport enthusiast, a seasoned collector, or someone in search of a prestige chronograph that offers both style and substance, this Rolesor Daytona delivers unmatched appeal.