Short answer
A fake Constellation Co-Axial Master Chronometer copies the Omega Constellation case and dial, and prints "Co-Axial Master Chronometer" on the dial. That printing does not make it a Master Chronometer. Master Chronometer is a METAS certification of a complete watch. A factory cannot issue it. The genuine 39 mm steel model runs calibre 8800 and ships with a METAS card that lists the movement number. A replica ships with a card that matches nothing.
Constellation Co-Axial Master Chronometer Fake Model: How to Judge Replica Versions
What the three terms mean
- Constellation: Omega model line. The 39 mm version has a date at 6 o'clock and claws on the bezel at 3 and 9 o'clock.
- Co-Axial: escapement with three pallet stones instead of two. It cuts sliding friction on the escape wheel teeth.
- Master Chronometer: METAS certification. Movement and cased watch pass 8 tests over 10 days.
Numbers to check
These figures come from Omega and METAS. A listing that contradicts them is wrong.
Constellation Co-Axial Master Chronometer Replica Watch: What to Check Before Buying
- Rate: 0 to +5 seconds per day after casing. Not -4/+6.
- Magnetic resistance: 15,000 gauss, measured in test.
- Case: 39 mm, 50 m water resistance, sapphire front and back.
- Movement: calibre 8800, 55 hour power reserve, one barrel, silicon balance spring.
- Price: steel on steel lists near 6,000 to 7,000 USD at retail. Replicas sell for 300 to 600 USD.
Where replicas fail
- Dial print. The "Co-Axial Master Chronometer" line sits above the date. On fakes the letters crowd the aperture or run off center.
- Date at 6. Check the font weight and the cut of the window. Replicas use a generic disc.
- Claws. The bezel claws must sit square on the case and grip the bezel edge. Bent or gapped claws are a fail.
- Caseback ring. Engraving on the real ring is deep and even. Laser etching on fakes is shallow.
- Balance wheel. Calibre 8800 is free sprung. It has two regulating weights and no index arm. Most replicas use an ETA 2824 clone with a regulator arm and a screw.
- Card. The METAS card carries the movement number. Ask the seller to read the number on the card and on the movement.
What a replica cannot do
No METAS card. No Omega service. No parts supply. No resale value. Water resistance is not tested after assembly. Rate and amplitude are unknown until a watchmaker measures them.
constellation co-ax master chronometer copy
Limits of this guide
Photos cannot confirm a movement. Only a watchmaker with the caseback open can. Ask for a clear photo of the balance and the rotor edge before you pay. If the seller cannot send one, treat the movement as unknown.