Strap for Speedmaster 60th Anniversary / Trilogy Box

The lug width measures 19.00 mm. This is the distance between the inner edges of the two connection lugs that attach the strap to the case. Verify with a caliper by measuring on the upper or lower lug of the case. This measurement is fixed and does not vary between examples of reference 311.10.39.30.01.002.

Black or dark brown alligator is the classic formal choice, with natural patina that ages beautifully. Military NATO echoes the aviation heritage and allows for quick changes. FKM rubber is ideal for daily sports use. Vegetable-tanned calf represents the balance between refinement and versatility. Each choice depends on context of use and the patina desired over time.

Use a spring bar tool. Position it in the lateral holes of the upper lug, compress slightly to release the spring bar, then remove the old strap. Insert the new strap by aligning the holes with the seats, press until you hear an audible click from the spring bar. Verify that the strap is secure. If you prefer assistance, the Casati Milano atelier offers strap changes by appointment.

Yes, if the lug width is exactly 19.00 mm. Verify the specifications with the seller before purchase. Artisanal straps online (such as those from milanostraps.it for the 19mm size) are tested for compatibility. Avoid straps of dubious origin: an Omega case deserves authentic materials and careful construction.

A quality artisanal alligator strap lasts 3–5 years with daily wear, depending on climate, frequency of wear, and maintenance. Vegetable-tanned leather ages naturally, developing characteristic patina. Casati Milano's 18-month warranty covers structural defects. Periodically clean with a damp cloth and apply leather-specific cream to extend both functional and aesthetic life.