The Omega De Ville Trésor 40mm with a 424 reference prefix is a slim, no-date, no-lume dress watch built around the co-axial Calibre 2500 with an Si14 silicon balance spring. Fakes of it fail on four points: the movement visible through the sapphire caseback, the dial's applied logo and text spacing, the engraved caseback data, and whether the serial numbers match the warranty card. Genuine examples pass all four checks; counterfeits almost never do.
What Is the Omega De Ville Trésor 40mm Ref. 424?
The 424 prefix covers the first-generation Trésor 40mm, Omega's extra-thin three-hand dress watch. Steel versions carry 424.13.40.20.xx references and gold versions carry 424.53.40.20.xx. Newer Master Chronometer Trésor models moved to the 435 prefix with Calibre 8930, so a 424 identifies the earlier Calibre 2500 generation.
How Do You Spot a Fake Omega De Ville Trésor 40mm?
Movement Seen Through the Caseback
Genuine watches have a sapphire display back showing a decorated Calibre 2500 with the co-axial escapement and a free-sprung balance. On the real movement the rotor engraving is crisp, the striping is cut into the metal, and the co-axial wheel stack is visible. Fakes usually hide a generic automatic or a decorated clone with printed rather than cut finishing.
Dial Details
The dial carries an applied metal OMEGA logo, a printed De Ville script, and faceted polished indices. Check letter spacing and alignment against an official photo, because counterfeit dials often stretch the kerning or set the text too high. Real dial printing stays clean under a loupe while fakes show fuzzy or doubled edges.
Caseback Engravings and Serial Numbers
Genuine casebacks are engraved with the reference number, the material mark, and the movement serial at consistent depth and in a consistent font. That serial should match the number on the movement and on the pictogram card supplied with the watch. A missing or mismatched serial is the strongest single fake signal.
Size, Weight, and Lume Checks
- Case diameter measures exactly 40mm across the bezel, not 41mm.
- 18k gold versions feel noticeably heavy and warm compared with plated brass or steel copies.
- The Trésor 40mm has no lume, so glowing hands or markers mean the watch is not genuine.
- There is no date window, so an aperture at 3 o'clock is a red flag.
Frequently Asked Questions
Does the De Ville Trésor 40mm Have a Date?
No. The 424 Trésor 40mm is a pure three-hand watch with no date aperture on the dial.
Is the Trésor 40mm Luminous?
No. Omega did not apply lume to the dial or hands, which keeps the watch a formal dress piece.
What Does the 424 in the Reference Number Mean?
It identifies the De Ville Trésor case family and generation. The following digits indicate case material, size, movement, and dial variant.
What Should You Verify Before Buying?
Ask for macro photos of the movement, the caseback engraving, and the paperwork, then compare the serial numbers across all three. A service record from an Omega-authorized center is the cleanest proof of authenticity. If the seller will not show the movement or refuses a return window, walk away.