A fake IW371771 is a counterfeit of the IWC Portugieser Chronograph reference, and the fastest way to identify one is to compare the dial text, case finishing, and movement through the display back against a genuine example. Most fakes of this reference fail on the small details: letter spacing in the dial printing, the crispness of the case edges, or the engraving on the rotor. If two or three of those details look soft, walk away.
What the IW371771 Reference Actually Is
The IW371771 belongs to the IWC Portugieser Chronograph family, a line built around a clean, highly legible dial with two chronograph subdials and applied numerals or indices. That design language is exactly why it gets copied so often. A simple dial is hard to fake, because there is nowhere to hide sloppy work.
Before you inspect anything, pull up the official reference data and a set of high-resolution photos. You need a baseline for dial color, subdial position, case proportions, and strap hardware. Authentication is a comparison exercise, not a gut feeling.
Dial and Hands Checks
- Printing quality. Genuine dial text is sharp under magnification. Fakes show thick, bleeding edges or uneven spacing.
- Subdial spacing. On copied movements, the chronograph subdials often sit slightly too close together or too far apart.
- Applied markers. Genuine indices are polished and sit level. Fakes are often glued slightly crooked or stand too tall.
- Hand finish. Look for burrs on the edges of the leaf or baton hands and mismatched lume color between hands and markers.
Case, Crown, and Pushers
Run a fingernail along the case flank and the lug edges. Genuine finishing is even, with a clean transition between brushed and polished surfaces. Fakes usually show wavy brushing, rounded lug tips, and a crown that feels gritty when wound. Press each chronograph pusher and listen: a genuine column-wheel or cam-actuated chronograph returns a defined, snappy click. A vague, mushy feel is a strong warning sign.
Caseback and Movement
Through the display back, check the rotor engraving, the finish on the bridges, and the presence of blued screws. Fakes frequently use unmarked or poorly stamped movements, and the rotor text is often the wrong font. Compare the movement layout against the manufacturer's published images rather than a seller's photo, since sellers crop and retouch.
Strap, Buckle, and Packaging
- Genuine leather straps have tight, even stitching and a clean cut edge.
- Buckle engraving should be deep and consistent, not laser-etched and shallow.
- Boxes and papers are the easiest things to counterfeit. Treat them as supporting evidence, never as proof.
Price and Seller Warning Signs
The single strongest signal is price. A Portugieser Chronograph listed far below the going secondary market rate is either damaged, stolen, or fake. Other red flags include stock photos instead of dated, in-hand images, pressure to pay outside a protected platform, no return window, and a seller who cannot send a short video of the running chronograph.
How to Verify Before You Buy
- Request timestamped photos of the dial, caseback, movement, and buckle.
- Ask for a short video showing the chronograph starting, stopping, and resetting to zero.
- Compare every detail with official reference images.
- Have an independent watchmaker open the case before the return period ends.
- Pay through a method that offers buyer protection.
FAQ
Are all fake IW371771 watches obvious?
No. Higher-tier copies can pass at arm's length. The tells appear under magnification and when the movement is inspected.
Can a serial number prove authenticity?
Only when it is checked with the manufacturer or a qualified service center. Numbers are copied and reused on counterfeits.
Is a service receipt enough proof?
It helps, but receipts can be forged. Match the serial on the paperwork to the serial engraved on the caseback.