Short answer
A fake IW371619 is a watch that carries the IWC reference number 371619 but was not made by IWC. That number sits in the IWC Portofino Chronograph line. Replicas copy the case shape, the dial layout, and the engraving on the back. They do not use an IWC movement, and they sell for a small fraction of the real watch.
What the real reference is
IW371619 belongs to the Portofino Chronograph family, reference 3716. Published specs for that family: stainless steel case, 42 mm diameter, sapphire crystal with antireflective coating, alligator leather strap, and IWC caliber 79320, a self-winding chronograph with a 44 hour power reserve at 28,800 vibrations per hour. Dial color and strap color change with the last two digits of the reference. Check the exact variant on IWC's own product page before you compare, because IWC has revised the line more than once.
If a seller cannot say which dial color 371619 should have, treat that as a signal. Reference detail is the first thing a knowledgeable seller knows.
Price gap
- Genuine Portofino Chronograph, secondhand: about $3,000 to $5,500 USD, based on box, papers, and condition.
- Replica, advertised: about $250 to $700 USD.
- Service on a genuine caliber 79320 at an authorized service center: several hundred dollars before parts.
A replica at $700 is still a $700 watch with no service network.
Checks that separate the two
Case and caseback
Engraving on a genuine IWC is cut into the metal, not laser-etched on the surface. Look at the reference number and serial with a loupe. Replica etching is shallow and letter spacing drifts. Caseback threads on replicas feel rough when you screw the back down.
Movement
Caliber 79320 follows the Valjoux 7750 architecture. Most replicas run an Asian 7750 clone. Rotor engraving on a clone is faint or absent. A watchmaker can open the back in minutes and name the base movement. Ask for a photo of the movement with the rotor visible before you pay.
Dial and hands
Subdial spacing follows the movement. A clone with a different base puts the subdials in the wrong place. On replicas the date font is wider, the applied markers sit off center, and the hands have flat bevels instead of polished ones.
Weight
Ask for a weight in grams. Steel cases of the same size land in the same range. A case that is 20 grams light is not steel at the same thickness.
What "Swiss replica" means
The term has no legal definition for watches. Sellers use it for a watch assembled in Asia with a few Swiss-sourced parts, often the balance or the mainspring. It does not mean the watch came from a Swiss factory, and no Swiss factory makes copies of IWC references.
Before you buy
- Ask for a timegrapher printout: rate, amplitude, beat error.
- Ask for the return window in writing.
- Compare the reference number against IWC's catalog.
- Check the seller's history on watch forums, not on the seller's own site.
Legal note
Counterfeit watches are illegal to import into the United States. US Customs can seize the shipment, and the buyer loses the money. Selling a counterfeit as genuine is fraud in every US state.