Short answer

A replica IW371632 is a copy of an IWC Portugieser Chronograph. The genuine watch has a 41 mm case, two subdials at 12 and 6, and IWC caliber 69355. A replica copies the outside. It does not copy the movement, the steel, or the finishing. Asking prices in the replica market run from about $80 to $800. Quality tracks price. In the US, selling or importing counterfeit goods is a federal crime.

The genuine reference

IW371632 sits inside the Portugieser Chronograph family, which holds many references that differ by dial color and case metal. IWC lists the current line with a 41 mm case, caliber 69355, 46 hours of power reserve, and a 4 Hz balance. The dial has a 30 minute chronograph counter at 12 and small seconds at 6. There is no date window. Confirm the exact dial and case metal for IW371632 on the IWC site before you compare it to any copy, because reference numbers in this family are close together.

Movements sellers name

  • A7750, a Chinese copy of the Valjoux 7750, often with a decorated rotor. It runs at 4 Hz and takes a 30 minute counter.
  • A Chinese column wheel copy sold as a 69355 clone. Ask for a photo of the movement and the caseback before you pay.
  • Quartz. Common at the low end. The chronograph hand often sweeps in one second steps.

Checks that separate tiers

  1. Subdial spacing. On the genuine dial the two subdials sit on one vertical line with even gaps to the center.
  2. Printing. Look at the IWC logo and the minute track under 10x zoom. Thick or merged letters mean a low tier case.
  3. Pushers and crown. Genuine pushers are round and sit flush with the case band.
  4. Caseback engraving. Depth and sharpness of the lettering vary a lot by factory.
  5. Strap. Most sellers ship a folded leather strap. Budget for a replacement.
  6. Timegrapher numbers. Ask for rate, amplitude, and beat error before shipping.

Legal and practical risk

US customs can seize counterfeit watches, and 18 U.S.C. § 2320 covers trafficking in counterfeit goods. Warranty and service support do not exist for these watches. A watchmaker who works on a Chinese 7750 may decline the job. Treat any purchase as a final sale.