Strap for Seamaster Aqua Terra 150M Master Co-Axial 38.5 Stainless Steel / Grey MOP

The lug width of the Omega Aqua Terra 231.13.39.21.57.001 is 20mm. This dimension is the standard reference for spring bars on this timepiece: it measures exactly the distance between the two horizontal pins located on the case. Always verify with a digital caliper or contact us for confirmation measurement before ordering.

For the Aqua Terra, we recommend alligator with vegetable tanning or box calf dyed in the mass. Alligator, with its natural scute pattern, amplifies the elegance of the 38.50mm case without appearing excessive. If you prefer sportier options, aged shell cordovan or a tomato tan leather offer refined patina. For humid environments, a leather-butadiene rubber blend maintains protection and comfort.

The change requires minimal tools: a fine cross-head screwdriver (1.5mm) and a bone or PTFE lever. Insert the lever under the lug terminal to gently separate the spring bars from the pins. Remove the springs, align the new strap with the holes, reinsert the spring bars ensuring they click fully home. If you prefer a qualified service, the Casati Milano atelier offers complimentary installation with purchase of a bespoke strap.

Yes, all straps from the 20mm collection in our catalogue are compatible. Universal 20mm spring bars fit perfectly on the attachment pins. If you order a personalized strap from the Casati Milano atelier, we specify the stitching thread, gold initials, and leather type exclusively for your model, guaranteeing impeccable finishing.

The duration depends on intensity of use and tanning method. An alligator or shell cordovan with vegetable tanning guarantees 18-24 months of daily wear before showing significant signs of wear. The leather's natural oils oxidize gradually, creating a desirable patina. Casati Milano offers an 18-month warranty on all bespoke straps and recommends rotating among at least three straps to extend the life of each one.