Quick answer
A counterfeit IW545187 most often fails on four checks: the caseback reference engraving, the case dimensions, the movement finish, and the dial print. Ask the seller for the six-digit reference and the case serial before you discuss price. If the reference does not match a real catalog entry, or the serial and reference are not engraved together on the caseback, walk away. Genuine hand-wound Portugieser references use an in-house calibre with striped bridges, polished screw heads, and a signed balance cock. Most fakes hide a cheap hand-wound or automatic movement behind the display back, and the cheapest ones ship with a solid caseback so the buyer never sees the movement at all.
Prerequisites
- 10x loupe or a phone macro lens
- Digital calipers, accurate to 0.1 mm
- Reference photos from an official catalog listing
- Seller permission to open the caseback, or a watchmaker present
How to check an IW545187
- Confirm the reference exists. Write down the full reference, IW prefix included, and compare it to the official catalog. A number that appears only on marketplace listings is a warning sign.
- Measure the case with calipers. Check diameter, thickness, and lug width against the published spec. Counterfeit cases run 0.5 mm to 1 mm off, and lug widths are frequently 20 mm where the real watch uses 21 mm or 22 mm.
- Read the caseback engraving under the loupe. Genuine engraving is cut into the metal with crisp edges and consistent depth. Laser-printed or acid-etched fakes look shallow, grainy, or slightly raised at the border.
- Compare the serial and the reference. Both numbers should appear on the caseback and match the warranty card. Mismatched digits between caseback and card is the most common tell on a fake.
- Inspect the dial print at 10x. Study the brand mark, the Swiss Made line, and the numerals. Fakes show uneven stroke weight, filled-in counters on letters, and a logo that sits too high or too low.
- Check the hands and small seconds. Compare hand length against the printed track, look at the finish, and watch whether the seconds hand sweeps without stutter. Flat, painted hands are a fake signal.
- Open the caseback. Look for striped bridges, chamfered edges, polished screws, and a signed balance cock. Count the jewels and compare that number to the published movement spec.
- Test the power reserve. Wind the watch fully and note when it stops. If the stated reserve is eight days, a movement that dies at 40 hours is not the calibre the seller claims.
- Feel the crown through the full wind. Genuine winding is smooth with defined resistance from stop to stop. Gritty, loose, or ratcheting crowns point to a generic movement.
- Examine the strap and hardware. Check the tang or deployant finish, stitching density, and spring bar quality. Soft-edged hardware rarely ships on a real reference.
- Verify the paperwork. The warranty card must carry the same reference and serial, a dealer stamp, and a date inside the production window.
- Compare the asking price to the secondary market. A genuine piece sold far under the going rate is damaged, stolen, or fake. No seller undercuts the market by 60 percent out of kindness.
Replica grades, if you knowingly buy a copy
Replica listings get sorted into rough tiers, and the labels mean less than the parts inside. A usable copy has a case that matches the real dimensions, a sapphire crystal with anti-reflective coating, applied indices instead of printed ones, and a movement you can identify by name. A weak copy has a chrome-plated brass case, mineral glass, a stuttering seconds hand, and dial printing that blurs under a loupe. Ask for macro photos of the caseback, the crown, and the movement before you pay, and treat any seller who refuses as a seller to skip.
Red flags that end the deal
- No caseback photo, or a photo showing a different serial than the card
- Reference number missing from the official catalog
- Price far below the secondary market average
- Seller refuses a watchmaker inspection or an in-person meeting
- Weight that feels light for a steel case of that size
Legal note
Selling a counterfeit as a genuine watch is fraud in the United States and most other markets, and customs agencies seize counterfeit shipments at the border. Buying a replica for personal use is a separate question from passing one off as real, and the two should not be confused.