Quick answer
The listing string "Omega De Ville Trésor 40mm 424" describes a counterfeit. Omega's Trésor is a thin dress watch, and its references do not sit in the 424 block that belongs to the De Ville Prestige family. When a seller mixes the Trésor name with a 424 code, the details are already wrong, and that is the first thing a buyer should notice. This guide explains what the genuine 40mm Trésor looks like and the checks that expose a copy. It covers identification only, not buying advice for counterfeits.
What the genuine 40mm Trésor is
The Trésor is Omega's slim, formal De Ville variant. A 40mm case on a dress watch is large by traditional standards, so the genuine model stays shallow (roughly 10mm thick) and sits close to the wrist. Genuine pieces use Co-Axial Master Chronometer movements with a silicon balance spring, sapphire on both sides, and dials with applied polished indices and printed text that stays razor sharp under magnification. Case metal, dial color, and bracelet or strap determine the exact reference, and each reference has eight segments, for example 435.13.40.21.02.001.
How to verify a Trésor 40mm before you buy
- Read the full reference and compare it against Omega's published catalog. The Trésor line has its own number family, and a 424 prefix points to a different model. Mixed codes are a counterfeit habit.
- Confirm the case dimensions. A 40mm Trésor is thin and light. A copy often measures several millimeters thicker because a generic movement cannot fit the original profile.
- Examine the dial up close. Genuine applied indices are polished on every face, the date window has a cut bevel, and the printing has no fuzzy edges or off-center lettering.
- Check the movement. Ask for a clear photo of the movement through the display back. A genuine Master Chronometer movement shows Geneva stripes, a decorated rotor, and an eight-digit METAS certificate number.
- Compare the caseback engraving. Genuine markings are cut deep with crisp edges. Most counterfeits use shallow laser etching that flattens under raking light.
- Ask for the Master Chronometer card, the pictograms card, and the serial number, then verify the serial through Omega or an authorized dealer.
- Have an independent watchmaker open the case. Movement identification takes minutes and settles the question faster than any photo.
- Compare the asking price against the current market for that reference. A 40mm Trésor at a fraction of market value is a copy.
Red flags in a listing
- Reference number that combines two Omega families.
- Photos that hide the movement or show a different watch than the one described.
- Serial number missing, blurred, or repeated across multiple listings.
- No box, no cards, and no service history for a modern reference.
- Pressure to pay by wire, gift card, or a payment app with no buyer protection.
Why it matters
Counterfeit watches are illegal to import into the United States and can be seized by customs. They carry no manufacturer warranty and no authorized service path, so a failed movement becomes an expensive paperweight. A Trésor copy also fails the one thing the real watch is built for: a thin, quiet profile on the wrist. If a deal looks too good for a 40mm gold or steel Trésor, treat the reference code as the first test and the movement as the last.