Short answer

Fake De Ville 424.10.40 means a replica of the Omega De Ville Prestige sold under the 424.10.40 base reference. That code covers stainless steel three-hand automatics with a 39.5 mm case, a date at 3 o'clock, and a Co-Axial calibre 2500 inside. Retail on the genuine watch runs about $3,300 to $4,400 USD. Replica sellers ask $120 to $500 for the same reference number.

How the reference code breaks down

A full number looks like 424.10.40.20.02.001. Six blocks, each with a meaning.

  • 424: De Ville Prestige case family.
  • 10: stainless steel case and bracelet.
  • 40: case size code. The physical diameter is 39.5 mm.
  • 20: movement group. Automatic with a Co-Axial escapement.
  • 02: dial code. 02 is silver in Omega listings.
  • 001: version and bracelet or strap variant.

Omega does not publish a complete public decoder for every block. The material, size, and dial blocks above match dealer and auction listings.

Genuine specification

  • Movement: Omega calibre 2500, automatic, Co-Axial escapement, 27 jewels, 25,200 vibrations per hour, 48 hour power reserve.
  • Case: stainless steel, 39.5 mm diameter. Water resistance 30 m, or 3 bar.
  • Crystal: domed sapphire with anti-reflective coating on the inner surface.
  • Caseback: sapphire display window, engraved with the reference number and serial.
  • Dial: silver or blue, applied Roman numerals or baton markers, date window at 3 o'clock.
  • Strap: steel bracelet or leather with a signed pin buckle.

What replica versions do

Replica 424.10.40 watches fall into three bands. Cheap builds near $120 use a plated brass case, mineral glass, and a low-grade automatic or quartz movement. Mid builds near $250 use 316L steel, sapphire glass, and a Chinese clone of the Miyota 9015. Top builds near $400 to $500 use 904L steel, a decorated clone, and a bracelet with solid end links.

Points that separate builds

  1. Caseback text. Genuine engraving is crisp and shallow. Most replicas show thick letters and wrong spacing between the reference digits.
  2. Dial print. CO-AXIAL and CHRONOMETER sit under the hands on the genuine dial. Replica fonts run wide, and the accent on the E of DE VILLE is often wrong.
  3. Date font and alignment. A replica date disc sits low in the window and uses a flat, wide numeral.
  4. Case profile. Genuine lugs curve down. Many replicas keep straight lugs and a thicker bezel.
  5. Weight. A genuine steel bracelet version weighs about 120 g. Common replicas come in at 90 g to 105 g.
  6. Rotor noise. A spinning rotor on a cheap clone is audible across a room. Genuine calibre 2500 runs quiet.

What no replica copies

Calibre 2500 uses a Co-Axial escapement with a three-level wheel. No clone in this price band reproduces it. Replicas use a standard Swiss lever escapement, so the beat is 21,600 or 28,800 vph, not 25,200. Service support is the other gap. Omega services the genuine watch. Replica owners replace movements instead.