Short answer

The string 424.13.40 belongs to the Omega De Ville Prestige line. Full references in that group include 424.13.40.20.02.001 (silver dial), 424.13.40.20.01.001 (black dial), and 424.13.40.20.03.001 (blue dial). A replica of this reference is a copy of a 39.5 mm steel Prestige with a Co-Axial automatic movement. Copies sold online differ from the real watch in four places: case diameter, movement type, dial printing, and caseback. The numbers below are the ones to compare before you pay.

What the reference number says

Omega does not publish a code table. The reading below comes from matching references across the De Ville Prestige catalog.

  • 424: De Ville Prestige, steel case.
  • 13: strap version. The 424.10 group in the same case uses a steel bracelet.
  • 40: case size code. 424.13.37 sits on a 36.8 mm case, so 40 marks the 39.5 mm case.
  • 20: movement group, automatic with date.
  • 02: dial color. 01 is black, 03 is blue.
  • 001: series variant.

Genuine baseline for ref. 424.13.40.20.02.001

  • Case: stainless steel, 39.5 mm across, thickness near 10 mm.
  • Crystal: sapphire front, sapphire display back.
  • Water resistance: 30 m, or 3 bar.
  • Movement: Omega calibre 2500 Co-Axial, automatic, 27 jewels, 25,200 vph (3.5 Hz), 48 hours of power reserve, COSC certified.
  • Dial: silver tone, date window at 3 o'clock, OMEGA and DE VILLE text under 12 o'clock, Co-Axial and Chronometer lines above 6 o'clock.
  • Strap: leather with a signed buckle.

Where copies diverge

  • Case size. Copies measure 38 mm or 41 mm at the bezel while listing as 39.5 mm.
  • Case thickness. A copy case runs thicker than the genuine profile.
  • Dial print. Letter spacing on OMEGA, the shape of the Ω glyph, and the weight of the Co-Axial line.
  • Date window. Frame shape, position, and font of the numerals.
  • Hands. Genuine hands have beveled flanks that catch light. Flat hands on a copy read dull.
  • Crown. The genuine crown carries the Ω mark.
  • Caseback. Genuine uses a sapphire back with an engraved reference and serial. Many copies use a printed plate or a closed back.

Movements found in copies

Copies ship with one of three movement types. A quartz module has a ticking seconds hand and a battery. An ETA 2824 clone from Seagull or Hangzhou is an automatic that beats at 28,800 vph. A Miyota 9015 is a Japanese automatic, also 28,800 vph. The genuine calibre 2500 beats at 25,200 vph. Movement source changes by seller and by batch, so ask for a photo of the movement and a timing reading on a timegrapher.

Check list before buying

  1. Measure the case at 3 and 9 o'clock. Target 39.5 mm.
  2. Check the date window against photos of the genuine dial.
  3. Look at the crown for the Ω mark and for a clean fit to the case.
  4. Ask for the calibre name and a movement photo.
  5. Read the caseback engraving. Reference and serial should sit on the rotor or the case rim, not on a sticker.
  6. Confirm strap material and buckle marking.

Price context

Authorized dealer list price for the reference sat in the low four figures USD. Used prices move with condition, box, and papers. Copy prices reported by buyers run from about USD 60 for quartz units to about USD 400 for automatic units with sapphire. Those figures come from buyer reports, not from a tracked index. Treat any seller quote as unverified until you see the unit.

What cannot be confirmed

No public test data covers dial metal, crystal source, case finishing, or gaskets on copies. Water resistance on a copy is unverified, so do not swim with one. Stock photos posted by sellers do not show the unit that ships. Serial numbers on copies do not resolve in any Omega database.