"Replica Constellation 131.20" is the phrase buyers use when they want a copy of the Omega Constellation Globemaster in its 39 mm two-tone form, the references whose case numbers start with 131.20. The short answer: the pick that survives scrutiny is a pre-owned genuine Globemaster in steel, and if you insist on the copy route, judge it on four things only, which are bezel fluting, pie-pan dial facets, hand-stack height and bracelet finishing. Those four checks separate the handful of credible builds from the bulk of what the wholesale market ships.

What the 131.20 reference identifies

Omega packs case material, diameter and movement into its reference strings. The Globemaster family carries numbers in the 131.20.39.20.xx pattern, where the 131.20 prefix marks a two-tone steel-and-gold case, the 39 states the diameter in millimeters, and the fluted bezel and pie-pan dial define the silhouette. Copies are sold under the same numbers, which is what makes the search phrase useful: you are not shopping for a generic Constellation, you are shopping for one specific dial architecture and one bezel treatment.

The genuine watch is a Master Chronometer, certified by METAS for precision and magnetic resistance, and it carries a co-axial movement rated to 15,000 gauss. No replica carries that certification. Treat any listing that implies otherwise as a warning sign about everything else in the description.

Criterion one: bezel fluting and case geometry

The fluted bezel is the hardest part to copy well. On a good build the flutes are cut, evenly spaced and catch light in a continuous run around the case. On a poor one they are stamped shallow, uneven at the 12 and 6 positions, and the transition from bezel to case band is soft where it should be a crisp step.

  • Check: case diameter with calipers, lug-to-lug length, and whether the bezel sits flush or floats above the case band.
  • Check: crown position and whether it seats into the case flank without a visible gap.

Criterion two: the pie-pan dial

The dial is a shallow pyramid with faceted inner slopes, and the printing has to sit on those slopes without distortion. Cheap copies flatten the pie-pan into a printed ring, or the facets are too deep and the hour markers tilt. Look at the applied markers under raking light: they should be parallel to each other and evenly set into the facet edges. Chapter-ring print should be sharp enough to read at arm's length.

Criterion three: movement, hand stack and crown action

Ask what movement is inside and expect one of three answers: a decorated clone of a Swiss automatic, a Japanese automatic, or a quartz. Hand-stack height is the tell. A watch with a thick hand stack sits proud of the dial and catches sleeves. Winding should feel smooth with no grinding, and the date, where fitted, should flip clean at midnight rather than drifting.

Criterion four: bracelet and finishing

Two-tone bracelets expose every shortcut. Gold-tone plating wears through at the clasp and the inner links within months. Solid end links should meet the lugs without rattle, the clasp should close with a firm click, and the brushed and polished surfaces should be separated by a clean line rather than a smeared transition.

Option A: pre-owned genuine Globemaster (top pick)

A used steel Globemaster from a reputable dealer is the only version of this watch that survives a service, holds value and can be authenticated.

  • Pro: certified movement, genuine finishing, real resale market, serviceable by any competent watchmaker.
  • Pro: no customs exposure and no risk of a seizure letter.
  • Con: several times the cost of any copy, and two-tone versions cost more again.
  • Con: you need papers or a dealer you trust, which takes research.

Use case: anyone buying one watch to wear for years, or anyone who wants the pie-pan dial and fluted bezel without thinking about it again.

Option B: two-tone steel and gold-tone replica

This is the build most people mean by replica Constellation 131.20. Quality spans a wide range, and the top of that range is genuinely wearable at arm's length.

  • Pro: correct silhouette, convincing dial facets when you buy from the upper tier, comfortable on the wrist.
  • Pro: low entry cost relative to the genuine reference.
  • Con: plating wear at the clasp is close to certain with daily use.
  • Con: no certification, no service path, and no resale value.

Use case: occasional wear, or a buyer who wants the look for a specific event and accepts that the bracelet will age faster than the case.

Option C: full gold-tone replica

Full gold-tone is the weakest category. The color is the hardest to hold, the weight is wrong, and the plating failure is more visible because there is more of it.

  • Pro: the strongest visual match to the solid-gold look from a distance.
  • Con: plating wear shows on every surface, not just the clasp.
  • Con: the weight and warmth of real gold cannot be imitated, and hands know the difference even when eyes do not.

Use case: photographic or costume use only. For regular wear, the steel-and-gold build ages better.

Legal and practical reality

Counterfeit watches infringe trademarks and are subject to seizure in the US and the EU. Customs holds parcels, and a seized shipment usually means the money is gone. There is also no service network: a failed movement in a replica is a replacement, not a repair. Weigh that against the price gap before you commit, and ask any seller for movement details, real photographs of the actual watch, and a return window in writing.