The short answer
A fake IW371785 is a counterfeit of an IWC Portugieser Chronograph from the 3716 family, and every one sold online is built in a Chinese workshop. There is no secret factory making an identical watch, and no gray-market version with genuine parts. What varies is tier: prices run from about $70 to $400, and the gap between the bottom and the middle of that range is wider than the gap between the top tier and the real thing.
What the reference actually is
The IW371785 belongs to the Portugieser Chronograph line: two registers with the chronograph minutes at 12 and running seconds at 6, feuille hands, applied numerals on a clean dial, stainless steel case in the 41 mm range, sapphire front and back, and an IWC automatic chronograph from the 69000 family inside. That list is your checklist. A replica either matches the layout or it does not, and the mismatch shows up in ordinary photos long before anyone needs a macro lens.
The three tiers you will run into
- Under $120. Quartz or a low-grade automatic, mineral glass, soft dial printing, and subdials that do not do what they should. A common trick is a 24-hour hand posing as a chronograph counter. Caseback engraving is shallow and laser-etched. This is a costume piece, not a watch.
- $150 to $250. Automatic 7750 clone, sapphire crystal, correct two-register layout, reasonable weight. This is the volume tier, and most wholesale sites are simply reselling the same watch with new photos.
- $300 and up. Closer case proportions, anti-reflective coating on the sapphire, sharper dial printing, hands with better length and curve, and a movement dressed with stripes and an engraved rotor. Caseback font and depth get close. Compare this tier against a genuine photo, not against another replica.
What to inspect before you pay
- Subdial function. Ask for a video. The top register should count chronograph minutes, the bottom one should run continuously as seconds. If the bottom subdial sits dead until you press a pusher, stop.
- Start, stop, reset. Pushers should feel crisp and the reset should snap to zero instead of drifting. A lazy reset on a 7750 clone is a service bill waiting to happen.
- Dial text. The brand name and "Automatic" should be crisp and evenly weighted, with no halo around the letters. Fuzzy edges appear in any 2x zoom.
- Hand shape. Feuille hands taper to a point and reach close to the minute track. Replicas often fit hands that are short or flat.
- Case finishing. Brushed flanks with polished bevels, sharp lug edges, no tool marks where the lugs meet the case.
- Weight and thickness. Steel should feel substantial for its size. A hollow case usually means a thin alloy that dents.
- Caseback. Reference numbers, the Probus Scafusia line, and engraving depth. Request one straight-on photo in daylight rather than a tilted shot in dim light.
Movement reality
Nothing in this price range carries an IWC movement. You get a 7750-derived automatic, or in cheaper builds a hand-wound or quartz unit, sometimes with a rotor finished to imitate something grander. Timekeeping is often fine out of the box, within ten or fifteen seconds a day on a good example, but servicing costs more than a replacement movement. Treat the watch as disposable and you will not be disappointed.
Sizing and fit
The Portugieser case wears large for its diameter because the dial is almost all crystal and the lugs are short. A replica with lugs that are too long or a case that is too thick will sit wrong on a 7 inch wrist, and that is something photos hide. Ask for the seller's measured case diameter with calipers and compare it to published specs for the reference.
What to pay
For a top-tier automatic with sapphire on both sides and a properly working chronograph, expect to land somewhere between $280 and $400. Anything priced above that is marketing. Anything below $120 is a different product category, and no amount of photo editing changes that. If a seller will not send a live video of the chronograph running, the price does not matter.
Bottom line
The fake IW371785 is only worth buying at the top tier, and only after you have seen the movement run on video. Check the subdials, check the reset, check the printing, and check the caseback engraving. If four of those look right, you are looking at the best version available. If one of them is off, there is another seller a click away.