Omega · Constellation

Strap for Constellation Co-Axial 31 Stainless Steel / MOP

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width

20mm

20 mm straps All Omega

Lug width20 mm

Case diameter31 mm

Reference123.10.31.20.55.001 (aka: 12310312055001)

FamilyConstellation

MovementOmega caliber 8520 Hours, Minutes, Seconds | Date | Chronometer, Co-Axial Escapement

CaseStainless Steel

Recommended spring bar

Spring bars Omega 20mm — 1.8mm diameter

Technical match for lug width and diameter · lug 20 mm · Ø 1.8 mm

View product →

All Omega spring barsOpen →

Straps for the Constellation 123.10.31.20.55.001 (aka: 12310312055001)

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Constellation 123.10.31.20.55.001 (aka: 12310312055001), seen from the bench

The Omega Constellation Co-Axial 31mm features a stainless steel case with mother-of-pearl dial, representing one of Swiss watchmaking's most iconic lines since its 1952 debut. This model combines Omega's precision chronometric standards with elegant proportions, making it distinctly wearable while maintaining excellent readability. The 20mm lug width accommodates contemporary strap requirements.

Frequently asked questions

What is the lug width of the Omega Constellation 123.10.31.20.55.001?

The <a href="/pages/termine-glossario/misura-ansa">lug width</a> of the Omega Constellation 123.10.31.20.55.001 is 20mm. This dimension is specific to the ladies' model and Constellation watches of this proportion. Always verify the measurement before purchasing a strap.

What is the best strap material for the Constellation 123.10.31.20.55.001?

For this delicate stainless steel case, we recommend <a href="/pages/termine-glossario/alligatore">alligator</a> or calf leather with <a href="/pages/termine-glossario/concia-vegetale">vegetable tanning</a> for formal elegance, or <a href="/pages/termine-glossario/shell-cordovan">shell cordovan</a> for a more sensual pairing. Rubber or NATO straps are ideal for sports use and offer greater moisture resistance.

How do you change the strap on an Omega Constellation?

The Constellation 123.10.31.20.55.001 is fitted with spring bars. For replacement, gently remove the bars, typically using a specialized tool. If you are not experienced, we recommend consulting a qualified jeweler or Casati Milano atelier for risk-free replacement.

Can I use an aftermarket strap on this model?

Yes, any strap with a <a href="/pages/termine-glossario/misura-ansa">lug width</a> of 20mm is compatible. However, to preserve the aesthetic integrity of a vintage or modern Constellation, we recommend choosing materials and finishes that reflect the spirit of the watch: elegant calf leather, structured <a href="/pages/termine-glossario/alligatore">alligator</a>, or premium quality sports NATO straps.

How long does a leather strap last on an Omega Constellation?

A quality leather strap, such as those made from <a href="/pages/termine-glossario/shell-cordovan">shell cordovan</a> or calf leather with <a href="/pages/termine-glossario/concia-vegetale">vegetable tanning</a>, typically lasts 3-5 years with regular use and proper maintenance. Periodic replacement preserves the elegance of the watch and prevents case deterioration caused by moisture or accumulated dirt.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

Request an appointment →

Casati Milano · Via XX Settembre 15, Milan · by appointment only