Strap for Seamaster Aqua Terra 150M Co-Axial 38.5 Stainless Steel / Silver

The lug width of the Omega Aqua Terra 231.13.39.21.02.002 is 20 millimetres. This is the distance between the two case attachments where the strap is fitted. To measure correctly, use a digital calliper to measure the internal width between the lug shoulders, not the external width of the case.

Dark brown alligator is the classic choice that enhances the Slate Grey dial and maintains the aesthetic balance of the 38.50mm case. For a more robust and vintage profile, vegetable-tanned calf develops patina over time. For summer use or daily wear, an FKM rubber strap guarantees decade-long durability. We recommend a personalised consultation at the Casati Milano atelier to explore all options.

To change the strap, you will need a spring bar tool. Position the watch with the lug facing towards you, insert the tool into the small hole under the attachment, pushing laterally to compress the internal spring. When the pin loosens, pull it out completely. Repeat for the second pin. Install the new strap ensuring the pins are correctly locked: they should click into position with a sharp snap.

Yes, any strap with a 20mm lug width is compatible. On milanostraps.it you will find a selection of straps ready for dispatch in alligator, calf, shell cordovan and rubber, all specifically sized for this measurement. Always verify the lug width of your watch before ordering to avoid errors.

A high-quality leather strap (alligator, vegetable-tanned calf, shell cordovan) lasts from 3 to 7 years with daily use, depending on the material and care. Alligator and shell cordovan are more resistant to moisture and develop a patina that makes them more attractive over time. Bespoke straps from Casati Milano include an 18-month warranty and are crafted from leathers selected for superior longevity.