Strap for Seamaster Aqua Terra 150M Co-Axial 38.5 Stainless Steel / Red Gold / MOP / Bracelet

The lug width of the Omega Aqua Terra 231.20.39.21.55.001 is 20mm. This measurement is taken from the inner edge of one lug to the inner edge of the other and is critical for strap compatibility. Do not confuse lug width with the case diameter (38.5mm): these are two independent measurements.

Given the stainless steel and rose gold case with mother-of-pearl dial, the recommended materials are: alligator (for classic elegance with evolved patina), calf leather (for everyday versatility), shell cordovan (for extraordinary durability and mirror patina), or FKM rubber for sporting contexts. Avoid materials that are too casual and would not respect the aesthetic standing of the model.

The strap is changed using a specialized tool (spring bar tool) to push the lug pins through the holes in the case. A stable work surface and a steady hand are necessary. To avoid scratches on the rose gold case, it is highly recommended to contact a professional or specialized craftsman such as Casati Milano, who has dedicated tools and insurance against damage.

Yes, there are quality aftermarket straps available for the 20mm size. Milano Straps offers a complete collection of compatible 20mm straps, customizable in length, finishes, initials, and stitching thread. For a completely bespoke strap, the Casati Milano atelier by appointment creates custom artisanal solutions with personal choice of leathers.

A quality leather strap (alligator, calf, shell cordovan) worn daily typically lasts 3-5 years before showing significant signs of wear. Factors such as exposure to water, sun, sweat, and frequency of use affect longevity. Milano Straps offers an 18-month warranty on bespoke straps, with the possibility of maintenance and replacement in the following 2-3 years.