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IW371651 is an IWC reference tied to the Portugieser Chronograph line. A replica of it is a counterfeit watch, priced from about $250 to $700. The copies use a 41 mm steel case, a bicompax dial, and a chronograph movement built in Asia. No replica carries an IWC calibre. IWC does not list IW371651 in its current online catalog. Confirm the dial color, case metal, and production year of the original with IWC or an authorized dealer before you compare.

Original specification

  • Case: stainless steel, 41 mm diameter, 13.1 mm thick
  • Movement: IWC calibre 69355, automatic, column wheel chronograph
  • Power reserve: 46 hours
  • Frequency: 28,800 vibrations per hour (4 Hz)
  • Crystal: sapphire, front and display back
  • Water resistance: 3 bar (30 m)
  • Dial: two subdials, small seconds at 6, chronograph minutes at 12
  • Strap: alligator leather with a steel pin buckle

These figures follow the Portugieser Chronograph 3716 family. Check them against the exact IW371651 listing, because IWC has shipped this case with several dials and strap sets.

Parts that differ on a replica

  • Case thickness. Copies run 0.5 mm to 1.5 mm thicker than 13.1 mm.
  • Movement. Asian Valjoux 7750 or a clone of calibre 69355. Rotor engraving shows wrong font and spacing.
  • Subdial spacing. The gap between the two registers sits wider on most copies.
  • Printing. "Schaffhausen" and "Automatic" show soft edges under a loupe.
  • Date window. The frame is thicker, and the aperture edge is not chamfered.
  • Hands. Leaf hands lose the polished bevel and look flat.
  • Strap. Embossed cowhide in place of alligator.

Price bands

Low grade copies sell for $80 to $200 and use quartz. Mid grade copies sell for $250 to $450. High grade copies with a 7750 movement sell for $500 to $700. An original IW371651 sells on the secondary market for several thousand dollars.

Checks before you buy

  1. Ask for a case back photo and read the reference engraving.
  2. Run the chronograph and watch the minute counter return to zero.
  3. Measure case thickness with a caliper.
  4. Inspect the rotor for lettering and finish.

Legal note

US Customs and Border Protection seizes counterfeit watches. Import of a replica violates trademark law. Resale carries the same risk. Confirm the status of any watch with IWC before purchase.