Short answer

A "replica Constellation Manhattan 40mm" is a copy of the Omega Constellation Manhattan with a 40mm case. Omega introduced the Constellation Manhattan in 1982. The fifth generation arrived in 2019 with three case sizes: 36mm, 39mm and 41mm. A 40mm figure appears in some earlier Manhattan references and in replica listings. Case diameters in replica listings are often rounded, so ask for a caliper measurement at the bezel.

What defines the Manhattan case

  • Four claws (griffes) at 3 and 9 o'clock, clamped over the bezel.
  • Half-moon facets on the bezel and the case sides.
  • Integrated mono-rang bracelet. No end links between the lugs.
  • Applied star at 6 o'clock on the dial.
  • Caseback with the Observatory medallion and eight stars.

Genuine specs to compare

  • Movement: Omega Co-Axial Master Chronometer calibers 8800 and 8801 in the 39mm models, 8900 and 8901 in the 41mm models.
  • METAS Master Chronometer certification: eight tests, magnetic resistance to 15,000 gauss.
  • Power reserve: 55 hours on caliber 8800, 60 hours on caliber 8900.
  • Case steel: 316L stainless steel. Omega does not use 904L, which is a Rolex material.
  • Crystal: domed sapphire with anti-reflective treatment on both faces.

Where replicas differ

  • Movement: Seagull ST2130, ETA 2824 clone or Miyota 9015 instead of a Co-Axial caliber. Most run at 28,800 vph.
  • Claw edges: rounded on copies, sharp on the original.
  • Bracelet: fewer removable links, looser tolerances at the clasp.
  • Caseback medallion: shallow relief. Star count and font vary by batch.
  • Water resistance: listings claim 50m or 100m. Ask for a pressure test record.
  • Weight: no public dataset compares replica and genuine weights. Weigh the watch if this matters to you.

Reference numbers

Fifth generation Constellation reference numbers begin with 131. Earlier Manhattan references carry other prefixes. A seller who cannot read the reference off the caseback has not inspected the watch.

Legal note

Omega is a trademark of Omega SA, part of the Swatch Group. Selling counterfeit goods is a federal crime in the United States under 18 U.S.C. 2320 and carries civil liability under the Lanham Act. US Customs can seize shipments.

Checks before purchase

  1. Case diameter in millimeters, measured at the bezel with calipers.
  2. Caliber name and beat rate.
  3. Photos of the caseback medallion and the clasp engraving.
  4. Pressure test result if water resistance matters.