🔹 Overview
The RL Cosmograph Daytona Ref. 126509-0002 is the ultimate expression of endurance, performance, and prestige. Introduced in 1963, the Cosmograph Daytona was created for professional racing drivers. Crafted entirely from 18 ct white gold, its bright black dial with steel sub-dials and diamond hour markers combines legibility, sporty elegance, and luxurious sparkle. A fixed tachymetric bezel enables precise speed measurement, while the 40 mm Oyster case with Triplock waterproof system ensures reliability. The Oyster bracelet offers comfort, strength, and refinement.

💎 Key Specifications
Reference: 126509-0002
Case: Oyster, 40 mm, 18 ct white gold
Bezel: Fixed, engraved tachymetric scale, 18 ct white gold
Dial: Bright black with steel sub-dials, diamond hour markers
Crystal: Sapphire, scratch-resistant
Bracelet: Oyster (flat three-piece links), 18 ct white gold
Clasp: Folding Oysterlock safety clasp with Easylink 5 mm extension
Movement: RL Calibre 4131, automatic chronograph
Power Reserve: ~72 hours
Functions: Hours, minutes, small seconds; central chronograph seconds; 30-min counter (3h); 12-hr counter (9h); stop-seconds
Water Resistance: 100 m / 330 ft

⏱️ Movement
Caliber: RL Calibre 4131 (automatic chronograph)
Features: Parachrom hairspring, Paraflex shock absorbers, COSC + RL certification
Power Reserve: ~72 hours
Frequency: 28,800 vibrations/hour (4 Hz)
Functions: Central hours, minutes, seconds; chronograph with 30-min and 12-hr counters; stop-seconds

✅ Conclusion
The RL Cosmograph Daytona 40 Ref. 126509-0002 is a professional racing chronograph that doubles as a symbol of prestige and timeless sophistication. Diamond-set dial, full 18 ct white-gold construction, and the legendary Calibre 4131 movement merge luxury and performance. Built to last, it is a legacy piece — an icon for collectors to treasure and pass down through generations.