A fake IW371621 is a counterfeit of the IWC Portugieser Chronograph reference IW371621, a 41 mm stainless steel chronograph with a two register dial and IWC's in-house calibre 69355. Almost every copy of this reference is built around a stock ETA 7750 or a Seagull ST19, dressed up with an engraved rotor, a printed dial, and a copied reference number on the back. The giveaway is the movement, not the dial. Look at subdial spacing, the date font, and the feel of the pushers, and a copy usually announces itself in a few seconds.
What the real reference is
The IW3716 generation arrived in 2020 and replaced the long running IW3714. The case is steel or gold depending on the variant, about 41 mm across and roughly 13 mm thick. The dial carries two vertical registers, a 30 minute totalizer at 12 and running seconds at 6, applied Arabic numerals, feuille hands, and a railway minute track. Water resistance is modest at 3 bar, so treat it as a desk watch. The crystal is box shaped sapphire with anti-reflective coating, which throws a slight distortion at the edges that copies rarely reproduce.
Inside sits the calibre 69355, an in-house automatic column wheel chronograph running at 4 Hz with about 46 hours of reserve. IWC finishes it with Geneva stripes, blued screws, and a rotor carrying the Probus Scafusia medallion. Older IW3714 examples used the 79350, which was built on a Valjoux 7750 base. That detail matters, because a counterfeiter will sometimes point at a 7750 and claim it is the same movement as the older one.
How copies are usually built
- Entry tier. Quartz or a low grade 7750 clone, mineral glass, printed instead of applied numerals, and subdials in the wrong place. The date sits too far from the centre and the pushers feel like a pen click.
- Mid tier. An Asian 7750 with a decorated rotor and a sapphire crystal. From a metre away it reads fine. In the hand, the chronograph seconds hand stutters on start and the crown threads are rough.
- Upper tier. A modified 7750 with better dial printing, a closer case profile, and sometimes convincing caseback engraving. It still has 7750 architecture underneath, so the balance cock and rotor bearing sit in the wrong position for a 69355.
IWC is not Rolex, so the counterfeit ecosystem around it is thinner. There is no catalogue of super clone IWC movements the way there is for a Submariner. What you get instead is a decent case with a stock engine inside.
Tells I check first
- Subdial placement and hand length. On genuine dials the hands reach the printed track exactly. Fakes leave them short.
- Date window font. Genuine IWC date discs use a specific typeface. Copies almost always use a generic ETA disc.
- Pusher action. A column wheel gives a light, crisp start and a clean reset. A 7750 feels stiffer and the reset snaps harder.
- Caseback engraving depth and the reference number. Laser etching looks shallow and grey. Genuine engraving has crisp edges.
- Rotor and bridge layout through the display back. The 69355 has its own geometry, and a 7750 is unmistakable once you know the outline.
- Strap hardware. Clasp engraving on copies is usually shallow, and the leather is stiff and plasticky.
Before money changes hands
Ask for clear photos of the movement, the caseback, and the dial shot straight on. A seller who will not open the back is telling you something. Check that the reference number on the caseback matches the paperwork. Price is the loudest signal: a steel IW3716 trades used in the low to mid four figures, so anything advertised at a few hundred dollars is counterfeit, and a seller asking four figures for a copy is running a fraud, not offering a bargain. If you can, have a watchmaker put it on a timegrapher. Rate, amplitude, and beat error differ enough between a 7750 and a 69355 to settle the question in a minute.
The legal side in the US
Importing counterfeit trademarked goods into the United States is illegal, and Customs can seize the shipment and pursue penalties. Selling counterfeit watches is a federal offense. Buying one knowingly carries less risk for an individual buyer, but you get no warranty, no service from IWC, no replacement parts, and no resale value. Independent watchmakers often refuse to touch counterfeits because parts are unavailable, which turns a cheap copy into an expensive paperweight after its first service interval.
Bottom line
A fake IW371621 lives or dies on its movement, and the movement is the one thing a counterfeiter cannot fake cheaply. If the price is too low, the seller will not show the back, or the pushers feel heavy, walk away. The genuine article is a quiet, well finished chronograph. A copy is a case with a story attached to it.