Short answer
A fake IW329066 is a counterfeit of an IWC Pilot's Watch Mark XVIII. Four checks catch most of them: case size, date window, movement beat rate, and caseback engraving. The real watch has a 40 mm case, a date at 3 o'clock, a movement that beats 8 times per second, and a serial number IWC can confirm.
Note on the number itself. IWC lists Mark XVIII references in the IW3270xx range and Top Gun pilot models in the IW3290xx range. IW329066 does not appear on IWC's public product pages. Confirm the reference with IWC or an authorized dealer before you pay. A reference that does not exist is the first sign of a counterfeit.
Case and size
Real Mark XVIII: 40 mm diameter, about 11 mm thick, 20 mm lug width, 6 bar water resistance. Steel case, brushed on the sides, polished at the bezel edge.
- Measure the case with calipers. Fakes run 41 mm to 43 mm.
- Measure thickness. A thick caseback adds 1 mm to 2 mm.
- Check lug width with a ruler. 22 mm lugs mean a fake case.
- Inspect the crown. It is signed and sits close to the case band.
Dial and date
The dial is matte black. The triangle at 12 has two dots. The date sits at 3 o'clock in a square window with a white date disc. Print edges are sharp under a 10x loupe. Fakes show fuzzy print, a date window that sits off center, and lume that spills past the marker edges. Charge the lume with a phone light. Super-LumiNova glows green-blue and fades over 6 hours to 8 hours. Fake lume dies in 20 minutes.
Movement
Caliber 35111. Base Sellita SW300-1. 25 jewels, 28,800 vibrations per hour, 42 hour power reserve, hacking, bidirectional winding.
- Timegrapher check. 28,800 vph equals 8 beats per second. A 21,600 vph reading means an ETA 2824 clone or a Chinese ST2130.
- Power reserve check. Wind it all the way and let it sit. Under 38 hours points to a fake.
- Rotor check. Engraving on fakes is shallow and the lettering sits off center. Ask a watchmaker to open the case.
Caseback, serial, papers
The caseback is solid steel with laser engraving: reference, serial, PROBUS SCAFUSIA, water resistance. Engraving depth is even. Fakes use acid etch that looks gray and shallow. IWC serials run 7 digits to 8 digits and sit in a company database. Ask a boutique or service center to match the serial to the reference. Box, papers, and warranty card add proof. IWC extends the warranty to 8 years when you register the watch.
Price signals
Mark XVIII retail sits near $5,000 to $5,700. Used prices in 2024 and 2025 ran about $3,800 to $4,800 for steel models on leather. A new IW329066 at $700 is a counterfeit. No wholesale channel sells these at 85 percent off.
Bottom line
Verify the reference exists. Measure the case. Read the beat rate on a timegrapher. Confirm the serial with IWC. Any one failure ends the deal.