Omega · Constellation

Strap for Constellation Co-Axial 27 Brushed Stainless Steel / Yellow Gold Claws / MOP

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

Lug width20 mm
Case diameter27 mm
Reference123.20.27.20.55.005 (aka: 12320272055005)
FamilyConstellation
MovementOmega caliber 8520 Hours, Minutes, Seconds | Date | Chronometer, Co-Axial Escapement
CaseMother of Pearl | Yellow Gold, Stainless 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

All Omega spring barsOpen →

Straps for the Constellation 123.20.27.20.55.005 (aka: 12320272055005)

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Constellation 123.20.27.20.55.005 (aka: 12320272055005), seen from the bench

The Constellation Co-Axial 27 is an Omega timepiece referencing 123.20.27.20.55.005, combining stainless steel and 18-karat yellow gold with characteristic four griffes on the bezel. It features a 27mm case diameter, mother-of-pearl dial, and 20mm lug width, housing the automatic Omega 8520 Co-Axial calibre for certified chronometry and reduced friction. This elegant model from the Constellation collection, with its refined proportions, represents over seventy years of Omega heritage since 1952.

Frequently asked questions

What is the correct lug width for the Omega Constellation 123.20.27.20.55.005?

The lug width of the Constellation 123.20.27.20.55.005 is 20mm. You can verify it by measuring the internal distance between the two pins where the strap attaches. This dimension is specific to this elegant feminine model of the collection and allows for a wide choice of compatible artisanal straps.

Which strap material pairs best with the Constellation 123.20.27.20.55.005 in gold and steel?

Genuine alligator represents the most natural pairing for its elegant profile: the regular grain dialogues perfectly with the classical geometry of the lugs. Alternatively, vegetable-tanned calf develops beautifully over time, or shell cordovan for a rich and luminous texture that amplifies the reflections of the mother-of-pearl dial.

How do I change the strap on this Omega?

The Omega Constellation 123.20.27.20.55.005 features removable spring bars. With the help of a specific tool or at a watchmaker's, you can gently remove the pins from the lugs, detach the old strap and attach the new one. If you are not experienced, we recommend contacting a specialized atelier such as Casati Milano to ensure precision and protection of the case.

Which aftermarket straps are compatible with the Constellation 123.20.27.20.55.005?

All straps made with 20mm lug width are compatible. On milanostraps.it you will find a complete selection of artisanal straps in alligator, calf, shell cordovan and rubber, customizable in exact sizes and details such as initials and stitching type, ready for shipment.

How long does a natural leather strap last on a watch worn daily?

Durability depends on the quality of the tanning, usage and maintenance. An artisanal strap in vegetable-tanned calf or alligator lasts on average 3-5 years of daily wear, developing a fascinating natural patina. Shell cordovan, thanks to its fibrous structure, has superior longevity (5-7 years). Casati Milano offers an 18-month warranty on all custom-made straps.

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.

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