The "123.10" prefix is an Omega product code for stainless steel Constellation watches. Reference 123.10.35.20.01.001 is a 35 mm steel Constellation Date with caliber 2500. Omega listed the 123.10 family from about 2005 into the mid 2010s. Counterfeits of these references appear on auction sites, social marketplaces, and replica forums. The fastest check is the movement beat rate. A genuine 35 mm 123.10 runs at 25,200 vibrations per hour. Most counterfeit movements in these watches run at 28,800.
What the 123.10 code says
Omega builds its reference (PIC) number in blocks.
- 123: Constellation family, men's.
- 10: stainless steel case and bracelet.
- 35 or 38: case diameter in millimeters.
- Next two digits: movement and version code.
- Last three digits: dial, bezel, and configuration.
Omega retired this numbering system. Current Constellation listings start with 131 and similar. A listing that calls a new watch "123.10" is using an old code or a copy of one.
Genuine specs to compare
- Caliber 2500 on 35 mm references: co-axial escapement, 27 jewels, 25,200 vph, about 48 hours of power reserve, COSC certified.
- Some 38 mm references in this range use caliber 8500: twin barrels, 39 jewels, 25,200 vph, about 60 hours of reserve.
- Case: steel, 100 m water resistance, sapphire crystal with anti-reflective coating on both faces.
- Bezel: held by four claws (griffes) that are part of the case.
Case and bezel tells
Genuine claws are cut from the same steel block as the case. They meet the bezel with no seam. On fakes the claws are often separate pieces pressed or glued in place, with a gap at the base or a soft edge under a loupe. Check the line between brushed and polished surfaces. Genuine finishing keeps a sharp border. Fakes round it off. The crown carries the Omega symbol, the correct diameter, and clean threads. Fake crowns sit smaller and show a shallow stamp.
Dial and date tells
- Applied five-pointed star above the "Constellation" script.
- Omega symbol above the Omega wordmark.
- Date window at 3 with a stepped frame and sharp font.
- "Swiss Made" at 6 o'clock, split by the minute track on some dials.
Fake dials show soft printing, wrong letter weight, and dust under the crystal. Lume plots should be flat and even. Compare hand length. Genuine hands reach the minute track.
Movement and caseback
Casebacks on the 123.10 range are either solid steel with the Observatory medallion or sapphire display backs, depending on the reference. Genuine engravings are deep and crisp. The rotor carries the caliber number, "Co-Axial", and the jewel count in a fine font. Counterfeit rotors use laser etching, wrong spacing, or a decorated ETA 2824 under a copied plate. Serial numbers sit on the movement and on the case. They should match each other and Omega records.
Bracelet, clasp, and price
The steel bracelet uses solid links and a signed folding clasp. Fakes use hollow end links, a shallow stamped logo, and end links that do not sit flush with the case. Used steel Constellation 123.10 watches sell in the low thousands of US dollars. A complete watch offered under about $700 is a warning sign. Boxes, cards, and manuals exist in counterfeit form, so papers alone prove nothing.
Verification steps
- Measure the beat rate on a timegrapher. 25,200 vph points to caliber 2500 or 8500. 28,800 vph points to a fake or a swapped movement.
- Compare the case serial and the movement serial with a 10x loupe.
- Order an Extract from the Archives from Omega. The service is paid and confirms the reference and the production date.
- Take the watch to an Omega authorized service center for a hands-on check.
What is not public
Omega does not run a free public serial database. Dial color codes and exact production dates for single 123.10 variants are not published. For those, a service center inspection is the reliable route.
Counterfeit watches are illegal to sell in the United States and the European Union. Customs agencies seize shipments.