Strap for Seamaster Aqua Terra 150M Master Co-Axial 34 Stainless Steel / Sedna Gold / Diamond / MOP

The lug width is 18mm. This dimension represents the internal distance between the lugs of the case where the strap fits. It is a measurement that remains stable regardless of the production year of the model. To verify it, measure the internal space between the two lugs: it must correspond exactly to 18mm to ensure a perfect fit.

To enhance the Sedna Gold, we recommend an alligator strap worked with vegetable tanning in cognac, barenia, or dark brown tones. This choice creates a fascinating material contrast with the lustre of the case. Alternatively, shell cordovan develops a deep patina over time, ideal for those seeking a strap that transforms with wear. A structured grey calf leather offers elegant neutrality for formal occasions.

Use a strap remover or a small flathead screwdriver to gently push the spring bars inward into the case. Once loosened, the old strap slides out from the lugs. Insert the new strap by threading one spring bar at a time into its seat, ensuring they are fully anchored. The operation takes just a few minutes of care and requires no specialized tools.

Yes, any strap with an 18mm lug width is compatible with the 231.25.34.20.55.005. Artisanal straps available online at milanostraps.it are specifically made in this dimension and customizable in material, color, and stitching. For a bespoke experience, the Casati Milano atelier creates custom straps with personal leather selection and an 18-month guarantee.

A premium leather strap (alligator, shell cordovan, quality calf) typically lasts 3-5 years under moderate daily wear conditions. Longevity depends on variables: humidity exposure, frequency of wear, periodic leather conditioning. Vegetable-tanned straps maintain softness and durability longer than industrially tanned leathers. With careful maintenance (occasional cleaning and conditioning every 6 months), many owners extend the strap's life beyond 5 years, witnessing the fascinating development of patina and character.