Strap for Constellation Co-Axial 31 Stainless Steel / Yellow Gold / MOP

The lug width of the Omega Constellation 123.20.31.20.55.002 is 18mm. This measurement is essential for strap compatibility and can be verified by measuring the space between the case attachment pins with a calliper or ruler. An 18mm strap will fit perfectly onto the lugs without creating gaps or overlaps.

The best strap depends on the intended use. For formal and evening occasions, we recommend a pearl grey alligator or dark brown shell cordovan, which harmonise with the mother-of-pearl dial and yellow gold details. For elegant everyday wear, a vegetable-tanned calf leather in cognac or light brown tones offers versatility and develops a natural patina over time. For smart-casual environments, an anthracite grey rubber or white NATO strap maintains refinement without functional compromise.

Strap replacement requires a specific tool called a spring bar tool. Position the watch in a stable holder, insert the flat tip of the spring bar tool between the lug and the pin, gently press downward to expand the internal spring, remove the pin, and repeat on the other side. Reverse the procedure to mount the new strap. It is advisable to proceed with caution to avoid scratching the case. For those who prefer professional assistance, the Casati Milano atelier offers a strap change service by appointment.

Yes, absolutely. Many 18mm aftermarket straps are perfectly compatible with the Constellation 123.20.31.20.55.002, provided the lug width is indeed 18mm. Specialist brands such as Milano Straps offer straps in alligator, calf and other fine materials, often with superior construction quality to the originals. It is important to verify the precise measurements and consider strap thickness to ensure balanced aesthetics.

The lifespan of a leather strap depends on the tanning method, frequency of use and environmental conditions. A quality vegetable-tanned calf can last 2-4 years with daily wear and proper care (drying after rain, protection from excessive heat). Alligator, being more durable due to the scale structure, tends to last 4-6 years. Shell cordovan, thanks to its density, can reach 5-8 years. Milano Straps guarantees 18 months on all artisan straps, but actual longevity significantly exceeds this threshold if the strap is properly maintained.