The replica Constellation 131.20 is a copy of Omega's 39 mm steel-and-gold Constellation Master Chronometer, usually built on a leather strap and offered with either a decorated Japanese automatic or a cloned Swiss-style movement. The genuine reference family (for example 131.20.39.20.02.001) measures 39 mm across, uses a sapphire crystal, and pairs stainless steel with Sedna or yellow gold on the bezel, claws, and crown. Replica versions match those dimensions closely, so the real gaps show up in the movement, the dial printing, and the gold tone.
What defines the Omega Constellation 131.20?
The 131.20 case code means 39 mm, steel and gold, delivered on a strap rather than a full bracelet. Omega builds it around a mono-bloc case with half-moon claws at 3 and 9 o'clock, an integrated lug profile, and a bezel engraved with Roman numerals. Inside sits a Master Chronometer caliber (8800 family) rated to 15,000 gauss and certified by METAS, with a date window at 6 o'clock on most dials.
Key genuine specs to compare against
- Case diameter: 39 mm, thickness roughly 12.4 mm
- Water resistance: 100 m (10 bar)
- Crystal: domed sapphire with anti-reflective treatment inside
- Strap: alligator-pattern leather with a folding clasp
- Movement: automatic Co-Axial, Master Chronometer certified
How close is the replica to the real watch?
Size and silhouette are usually accurate on mid-tier and high-tier replicas, because the case is a simple round shape that CNC machining handles well. Weight is where gold versus plating becomes obvious: a genuine Sedna gold bezel and claws carry real mass, while a plated replica feels lighter in the hand. Dial texture is the second tell, since Omega's PVD-treated dials shift tone under angled light and cheaper copies stay flat.
What movement powers replica 131.20 watches?
Most replicas run a Miyota 9015, a Seagull ST2130, or a Hangzhou automatic, all beating at 28,800 vph with a smooth sweep. Higher grades add engraved rotors, blued screws, and a Co-Axial-style bridge plate so the caseback looks convincing through the sapphire display. None of them are true Co-Axial escapements, and none carry METAS certification.
Movement tiers at a glance
- Budget: basic 8215-style automatic, no decoration, loud rotor
- Mid: Miyota 9015 or ST2130, hacking, decent regulation
- High: decorated clone with engraved bridges and a labeled rotor
Which details expose a low-grade copy?
- Gold tone reads orange or washed out next to real Sedna gold
- Roman numerals on the bezel are shallow or filled unevenly
- Claws sit proud of the case instead of flush
- Dial text is blurry, or the star sits off center
- Date font is too wide and the wheel does not sit level
- Caseback engraving lacks depth and the seahorse detail is soft
- Strap stitching is uneven and the clasp feels thin
What should a replica Constellation 131.20 cost?
Entry copies sell between $80 and $150 and rarely survive daily wear for long. Mid-tier builds land near $180 to $350 with a serviceable automatic and a correct 39 mm case. Top-grade versions run $400 to $700 and are the only tier worth comparing side by side with the genuine piece.
Frequently asked questions
Is 39 mm accurate for a dress watch?
Yes. The 131.20 is a true 39 mm case, which wears close to a Datejust 36 with more presence on the wrist. It suits wrists from about 6.5 inches upward.
Does the replica keep 100 m water resistance?
Assume it does not. Gaskets and caseback torque are inconsistent on copies, so treat any replica as splash resistant and keep it away from pools and showers.
How do I check quality before buying?
Ask for macro photos of the bezel numerals, the dial text, the crown, and the caseback. Request a video of the seconds hand sweep and the date change to confirm the movement behaves correctly.
Bottom line
The replica Constellation 131.20 gets the size, the claw lugs, and the general look right at mid-tier and above. The gold tone, dial finish, and movement authenticity are the three areas where money buys visible improvement, so inspect those first.