Short answer
A fake IW371660 is a counterfeit copy of an IWC Portugieser Chronograph. The code sits in the IW3716xx block. The real watch uses an in-house caliber 69355, a column wheel chronograph, a 41 mm steel case, and a 46-hour power reserve. Counterfeit sellers copy the case, dial, and strap. They do not copy the movement. Fake listings run $300 to $900. IWC lists the steel Portugieser Chronograph on leather near $7,900 in the US. Used genuine examples trade near $5,500 to $6,800.
Genuine reference facts
Reference codes in the IW3716xx block share one case and one movement. The final digits change the dial color, hands, and strap. Not every code appears in every catalog year. Published specs for the line:
- Case: stainless steel, 41.0 mm across, 13.1 mm thick.
- Movement: caliber 69355, automatic, column wheel, 46-hour power reserve.
- Dial: date at 3, 30-minute counter at 12, small seconds at 6.
- Crystal: sapphire front and caseback.
- Water resistance: 30 meters.
- Strap: alligator leather or steel bracelet, set by the code.
Confirm the exact code on the caseback before you compare a seller's photos to catalog images.
What separates a fake from a real one
- Movement. Ask for a caseback photo with the rotor in view. Caliber 69355 shows a column wheel and engraving in a set font. Fakes show a generic Chinese chronograph movement or a 7750 clone.
- Subdial spacing. Both counters sit at 12 and 6. Fakes place them off center and the hands land past the printed track.
- Date window. Real date wheels use a thin font. Fakes use a wide font and the wheel sits low in the window.
- Caseback text. Reference and serial numbers use laser etching at set depth. Many fakes use shallow stamping.
- Chronograph feel. Press the pushers on a real 69355. Start and stop feel crisp at the column wheel. A 7750 clone feels soft and the reset snaps hard.
- Weight and finish. A steel copy weighs close to the real watch, so weight proves little. Look at the bevels and the brushing direction on the lugs.
Price and paperwork checks
Price is the fastest test. A watch that retails near $7,900 does not sell new for $400. A second-hand fake listed at $1,500 is still a fake. Ask for the invoice, the warranty card, and the box. IWC warranty cards carry the reference, the serial, and the dealer stamp. A serial that does not match the caseback is a problem. IWC service centers can check a serial against a reference. A counterfeit will not pass that check.
US law and risk
US law bars counterfeit watches. Importing one is illegal under 19 U.S.C. § 1526, and CBP seizes shipments at ports and in the mail. Trafficking in counterfeit goods is a federal crime under 18 U.S.C. § 2320. A first offense carries up to 10 years in prison. Buying a fake for personal use is not the same charge as selling one, but the import ban still applies. A fake has no warranty, no parts support, and no trade value at a dealer.
What a fake does not include
No warranty. No service from IWC. No spare parts. Movement accuracy on a $400 copy drifts, and a 7750 clone needs service that costs more than the watch. Keep these points in mind before you compare listings.