Strap for Cosmograph Daytona Stainless Steel / Yellow Gold / Black MOP Diamond

The lug width of the Rolex Daytona 116503-0009 is exactly 20 millimetres. This measurement represents the distance between the two lugs of the case where the strap attaches. It is essential to measure accurately using a digital calliper or flexible ruler positioned perpendicularly inside the lugs, in the area closest to the case. Even a minimal measurement error can compromise the aesthetics and fit of the strap on the wrist.

Structured alligator and soft calf leather are the materials most coherent with the chrono-elegant identity of this reference. Alligator emphasises the modern construction of the bicolour case through its geometric grain, whilst calf leather introduces tactile softness that balances the metallic hardness of gold and steel. Vegetable tanning is advisable for those seeking a natural patina that refines over time. Shell cordovan is a premium alternative if you accept an initial four-week break-in period, after which it develops superior impact resistance compared to pure calf.

Strap replacement requires a spring bar tool to remove the elastic pins that anchor the strap to the lugs. Position the tool in the lateral slot of the pin, apply gentle pressure inward and simultaneously move the strap—the pin will release. Reverse the operation to mount the new strap. If unfamiliar with the procedure, entrust the task to a certified watchmaker or our Casati Milano atelier to avoid scratching the lugs.

Yes, provided the lug width is 20 millimetres and the thickness at the attachment zone is between 3.5 and 4.5 millimetres. Be cautious of straps that are too rigid or excessively flexible, as these would compromise the fit on the case. Bespoke artisanal straps—such as those crafted by Casati Milano—guarantee superior construction quality and longevity compared to generic industrial products, preserving the aesthetic value of your bicolour case.

Lifespan depends on material and intensity of use. A vegetable-tanned calf strap typically lasts 3-5 years with moderate daily wear, whilst alligator and shell cordovan can endure 5-7 years owing to their more robust fibrous structure. Continuous exposure to sunlight, humidity and perspiration accelerates ageing. An artisanal strap from Casati Milano, crafted from premium leathers with sartorial finishing, is covered by an 18-month warranty on manufacturing defects and can be repaired or regenerated at the atelier to significantly extend its lifespan.