A fake IW371771 is a counterfeit or replica copy of the IWC Portugieser Chronograph reference. The genuine watch is a stainless steel chronograph with a polished case, a clean dial with two subdials, and an in-house automatic movement, so most fakes give themselves away through dial printing, case finishing, movement type, and a price that sits far below the real market.

Counterfeit or replica: what the search term really covers

People use "fake IW371771" for several different things, and the distinction matters when you are buying or selling.

  • Counterfeit: a watch built to imitate the original and sold as genuine, often with copied packaging and paperwork. This is fraud.
  • Replica: a copy that is openly sold as a copy, without a claim of factory origin.
  • Franken watch: a genuine case or dial mixed with aftermarket, donor, or refinished parts, which can be the hardest version to catch.

All three can appear in a listing described as an IW371771, so the first question is not "is it real" but "what is the seller claiming it is."

Why the Portugieser Chronograph gets copied

The design is simple, and simple is easy to imitate at a glance. A wide polished case, thin bezel, applied Arabic numerals, leaf-shaped hands, and two subdials read clearly in small photos, which is exactly how most online sales happen. The real watch also carries a price that makes a cheap lookalike tempting, so counterfeiters focus on the dial side and hope nobody asks for a movement shot or a service history.

How to spot a fake IW371771

Dial and hands

  • Printing should be crisp and level, with no fuzzy edges, bleeding, or slightly crooked text.
  • Applied numerals should sit flat and show a polished bevel that catches light, not a flat stamped surface.
  • Subdial spacing and hand lengths should look balanced. On many fakes the subdials sit too close together or too far from center.
  • The date font and window edge are common weak points. A rough cut or oversized numeral is a warning sign.

Case, crown and pushers

  • Look at the transition between brushed and polished surfaces. Genuine finishing has a sharp, straight line; fakes often show a soft, wavy blend.
  • Lugs should be even in thickness and angle. Crooked or thick lugs show up fast in a straight-on photo.
  • The crown and chronograph pushers should thread and press with a firm, even feel. Mushy pushers or a wobbly crown point to a cheap movement inside.

Movement and caseback

If the reference has a display back, ask for a clear movement photo. Genuine IWC chronographs use a finished automatic chronograph caliber with visible perlage, Geneva stripes, and engraved bridges. Many fakes hide a generic 7750-derived chronograph or a quartz module behind a decorative plate, and the giveaway is often a rotor that looks stamped rather than engraved, or screws that are the wrong shape.

On the outside, check the reference and serial engraving. It should be clean, consistent, and match the paperwork. Ask for a photo of the caseback and the area between the lugs, not just a dial shot.

Weight, sound and feel

A steel chronograph of this size should feel substantial in the hand. A hollow rattle when you shake it, a rotor that spins loudly, or a case that feels light for its size are all reasons to slow down.

Red flags in a listing or a meetup

  • A price far below what comparable examples sell for, with a story about why it is cheap.
  • Stock photos, blurry photos, or no movement and caseback images at all.
  • A seller who pushes you to pay outside a protected platform or refuses returns.
  • Box and papers that look new while the watch looks worn, or numbers that do not match.
  • Pressure to decide quickly, or a meeting place chosen to avoid a proper inspection.

Before you buy or sell

Compare the asking price against several current listings for the same reference, then have the watch inspected by an independent watchmaker who works on IWC. A short inspection costs far less than a counterfeit. If you are the seller, clear movement photos, caseback photos, and a service record answer most authenticity questions before they are asked.

If you already own a fake

Stop wearing it as if it were genuine, and do not pass it on as an original. If you bought it believing it was real, keep the listing, messages, and payment record, contact the platform or payment provider, and get a written opinion from a watchmaker. That document is usually what makes a dispute possible.

For buyers who simply want the look of a Portugieser Chronograph without the original price, an openly sold replica is a different purchase from a counterfeit sold as genuine. Knowing which one you are looking at is the whole point of checking the details above.