Strap for Seamaster Aqua Terra 150m Master Co-Axial 41.5 Stainless Steel / Black / Bracelet / Golf

The lug width of the 231.10.42.21.01.004 model is 20mm. This dimension is a structural specification of the 41.50mm steel case and is non-negotiable: a 19mm strap will create play, while a 21mm strap will not fit correctly. Always measure with a digital caliper perpendicular to the case, measuring the internal distance between the two spring bars.

For the 231.10.42.21.01.004 we recommend: Nile alligator to maximize aesthetic contrast, vegetable-tanned calf for a patina that visibly ages, shell cordovan to optically reduce the case diameter, NATO or FKM rubber for nautical use. The choice depends on your primary use context and desired aesthetics.

The Omega Aqua Terra 231.10.42.21.01.004 uses a standard system with removable spring bars. You need a spring bar tool: position the notch under the spring bar, apply downward pressure and the spring bar retracts, allowing strap removal. Insert the new strap aligning the holes with the spring bars, and the system locks automatically. If you prefer professional assistance, Casati Milano offers strap changes by appointment.

Yes, provided the strap is specifically designed for a 20mm lug width. You can choose any 20mm strap available online: Milano Straps offers a complete selection of compatible straps in alligator, calf, shell cordovan and rubber, customizable in sizes, initials and stitching color. Always verify the attachment tolerance before ordering.

A high-quality leather strap (alligator or vegetable-tanned calf) on a sport watch like the Aqua Terra typically lasts 4-6 years of daily use, with proper maintenance. Durability depends on: sun exposure, humidity, frequency of use, leather thickness (1.3-1.5mm ensures longevity), seasonal care. Casati Milano offers an 18-month warranty on all custom straps, with post-warranty service available.