Short answer
An Omega reference that starts with 123.10 is a stainless steel Constellation. The digits break down this way: 123 is the Constellation collection code, 10 is the case metal code for steel, and the next two digits give the case diameter in millimeters. A 123.10.35 reference is a 35 mm steel Constellation; a 123.10.38 reference is a 38 mm steel Constellation. Omega does not license, manufacture, or sell a "1:1 replica" of any of these references. Listings that use that term are unauthorized copies, and the watch they ship usually differs from the genuine article in case profile, bracelet taper, movement, and dial printing.
What the 123.10 code tells you
- 123: Constellation collection.
- 10: stainless steel case and bracelet.
- Next two digits: case diameter in millimeters, such as 35 or 38.
- Following digits: movement family and dial variant codes.
- Final digits: specific dial, bracelet, and market variant.
Genuine 123.10 references built through the 2000s and 2010s carry a Co-Axial escapement, the Constellation griffe claws on the bezel at 3 and 9 o'clock, an integrated bracelet, and a star emblem on the dial. Later examples add Master Chronometer certification, which is tested and documented by METAS rather than by the seller.
Prerequisites
- A clear photo of the caseback, dial, and clasp from the listing.
- The seller's stated reference number and movement serial number.
- A loupe or a phone camera with macro mode.
- The full eight-digit reference number you are comparing against.
How to check a 123.10 Constellation against a replica listing
- Compare the full eight-digit reference engraved on the caseback to the reference the seller advertised.
- Measure the case across the bezel from 3 to 9 o'clock, excluding the crown, and confirm it matches the diameter encoded in the reference.
- Inspect the griffe claws on the bezel; on genuine Constellations they are polished, symmetrical, and cut into the case.
- Check the bracelet end links for a flush fit against the case, with no gaps or movement.
- Examine the dial printing under magnification and confirm even spacing and crisp serifs.
- Read the movement markings, or have a watchmaker open the case, and confirm the caliber matches the reference.
- Request the movement serial number and have it checked against the records an Omega service center holds.
- Weigh the watch and compare it to a documented genuine example of the same reference.
Where replica listings fall apart
Most "1:1" Constellation copies run a generic automatic movement, either a Miyota derivative or a Chinese clone, instead of a Co-Axial caliber. The winding feel, beat rate, and power reserve give that away within a minute of handling. Bracelet construction is the second giveaway: copies use folded links and hollow end links, while genuine Constellations use solid links with a machined clasp. Water resistance claims are rarely tested, and gold plating on two-tone versions wears through in months.
Legal and practical risk
Counterfeit watches infringe Omega's trademarks, and importing them into the United States is prohibited even for personal use. Shipments are subject to seizure by U.S. Customs and Border Protection. There is no warranty, no parts support, and no service path for a counterfeit, which is why watchmakers decline to repair them. If you want a Constellation 123.10, buy through an authorized dealer or a verified pre-owned seller, and treat any "replica 123.10" listing as a copy of unknown origin with no resale value.