Strap for Day-Date 40 White Gold - Diamond / Black

The lug width of the Day-Date 40 228349rbr-0002 is 20 mm. This is the standard measurement for this model, requiring 20 mm straps to fit correctly within the lug slots of the Oyster case. Straps of different widths (19 mm or 21 mm) cannot be used as they will not seat vertically in the case's attachment points.

For the Day-Date 40 228349rbr-0002 in white gold, we recommend black or dark brown alligator leather with vegetable tanning. This material enhances the formality of the watch and creates a striking contrast with the white gold case. Alternatively, shell cordovan in burgundy tones or box calf in dark shades maintain aesthetic refinement with superior durability against daily wear.

To change the strap on the Day-Date 40 228349rbr-0002, you must remove the lug pins. Use a precision tool (spring bar tool) or visit an authorised service centre. The pins are small cylindrical elements with internal springs: insert the tool into the lateral groove, gently lever to release, then remove the old strap. Thread the pins through the new strap and insert the lug into the case until it clicks into position. Verify that the lug is fully seated before wearing.

All 20 mm straps are compatible with the Day-Date 40 228349rbr-0002. It is essential that the width is precise (20 mm measured internally between the pins), regardless of material: alligator, calf leather, shell cordovan, textile, or FKM rubber. High-quality artisanally-made straps—crafted with vegetable tanning—preserve the watch's aesthetic value and develop patina over time, unlike mass-produced alternatives.

The lifespan of a leather strap depends on usage intensity, climate, and material. A quality alligator or calf leather strap, worn daily, maintains structural integrity for 3–4 years. Shell cordovan, owing to its density, can exceed 5–6 years without failure signs. Leather wears first in contact areas (underside of wrist) and at buckle holes. To extend longevity, rotate between different straps and store in a dry environment. Casati Milano provides straps with an 18-month warranty against manufacturing defects and repair services.