Strap for Constellation Co-Axial 31 Yellow Gold / MOP

The lug width of the Constellation 123.50.31.20.55.002 measures 18 millimetres. This measurement is the standard reference for Omega on this model and represents the ideal proportion with the 31 millimetre case diameter, ensuring elegant and harmonious proportions on the wrist.

For yellow gold, alligator and vegetable-tanned calf leather are the most elegant choices. Alligator maintains a sober austerity that does not compete with the precious metal, while calf develops an amber patina over time that amplifies the luminosity of gold. Shell cordovan is the premium solution for those seeking natural lustre and decade-long longevity.

The change is made through the spring bars located at the ends of the case. Using a dedicated tool (spring bar tool), gently compress the bar to release it from its seat and slide it upwards to extract it. Insert the new strap so that the spring bar passes through both lugs, then release so that the bar returns to its seats. Verify the correct position before wearing the watch.

Yes, all straps with 18 millimetre lug width are compatible with the Constellation 123.50.31.20.55.002. Standard pre-assembled straps can be ordered online; for specific length requirements or customisation, the Casati Milano atelier creates bespoke straps with your personal choice of leather and stitch colour.

Durability varies depending on the material and frequency of use. High-quality artisanal alligator maintains structural integrity for 4-6 years of moderate daily wear; vegetable-tanned calf, being more delicate, requires servicing every 3-4 years; shell cordovan, due to its density, can exceed a decade. Direct sun exposure and humidity accelerate ageing. Regular maintenance – avoiding excessive water and heat – significantly extends the life of the strap.