Short answer
A fake IW371473 copies the IWC Portugieser Chronograph. The real watch is a 40.9 mm steel chronograph with a 30-minute counter at 12 o'clock, running seconds at 6 o'clock, and a mechanical movement that beats 8 times per second. Most counterfeits fail on the movement, the subdial spacing, and the caseback engraving.
What IW371473 is
IW371473 is an IWC reference in the Portugieser Chronograph family. The line uses a steel case that measures 40.9 mm across and 12.3 mm thick. Water resistance is 30 m. The crystal is sapphire, and many references add a sapphire caseback.
Portugieser Chronographs in this group run on caliber 79350. That movement comes from the Valjoux 7750 base. It runs at 28,800 vibrations per hour and holds about 44 hours of power reserve. IWC finishes the movement in Schaffhausen and engraves the rotor with "Probus Scafusia."
Reference numbers in this family change the dial color, the hands, and the strap. The case and the movement layout stay the same. Confirm the dial and strap for IW371473 with IWC before you compare a watch to photos online.
Tells on a counterfeit
Movement
Ask for a photo of the movement or a video of the running seconds. The real small seconds hand at 6 o'clock sweeps in 8 steps per second. A quartz fake ticks once per second. A Seiko VK64 or Miyota 6S21 meca-quartz movement ticks at that rate too, and the chronograph seconds hand jumps instead of sweeping.
Cheap mechanical copies use a Seagull ST19 or a low-grade 7750 clone. The rotor engravings sit shallow. The perlage and Geneva stripes are missing.
Dial and subdials
The 30-minute counter sits at 12 o'clock on the real watch. The running seconds sit at 6. On many fakes the two subdials sit closer to the center, or the spacing is uneven.
Printed text on the real dial reads "IWC" and "Schaffhausen" with sharp edges. Fakes show thick paint, wrong letter spacing, or a wrong "International Watch Co." line.
Case and caseback
The caseback carries the reference number, the case number, and the model name. Stamp depth matters. Laser-etched numbers sit flat and look gray next to a real engraving.
The crown has the IWC fish logo. Pushers at 2 and 4 o'clock have a firm, short travel. Fakes feel soft or grind.
Red flags in a listing
- Price under about $2,000 for a steel Portugieser Chronograph. Used real ones sell for more.
- Photos with no caseback shot.
- Box and papers with numbers that do not match the watch.
- Seller who refuses a video of the chronograph start, stop, and reset.
- Serial number that returns no record from IWC.
Before you pay
- Get the reference and case number from the caseback.
- Ask IWC to confirm the number and the original dial and strap.
- Request a video of the chronograph running and resetting.
- Compare subdial positions to an official IWC photo of IW371473.
- Use an escrow service or a credit card. Do not send a wire.
- Have a watchmaker open the watch. Check for the 79350 stamp and the correct base plate finish.