The short answer
A "replica IW371479" is a counterfeit copy of an IWC Portugieser Chronograph. It can look convincing in a listing photo and feel wrong the moment you handle it. It also infringes IWC's trademarks, and in the US, importing or trafficking in counterfeit goods is a federal offense. I'm not going to steer you to a seller. What I can do is explain what the genuine reference is, where copies give themselves away, and what to buy instead if the Portugieser look is what you're after.
What the IW371479 actually is
The reference belongs to IWC's Portugieser Chronograph family, the two-register design with a 30-minute totalizer at 12 o'clock and running seconds at 6. Across that family you get a 41 mm stainless steel case, a domed sapphire crystal, feuille hands, applied Arabic numerals, and a railway-track minute ring. Water resistance is 30 meters, which is to say splash-proof and nothing more.
Movement depends on the production year. Earlier Portugieser Chronographs ran calibre 79350, a heavily reworked Valjoux 7750, while later ones use the in-house 69355. IWC quotes roughly 44 to 46 hours of power reserve depending on which one you have. Reference-level details like dial finish, bracelet, and movement vary by generation, so check any spec sheet, including the one you're reading, against IWC's own records before you treat it as final.
Where "1:1" copies fall apart
- Case dimensions copy well. Case finishing does not. Look at the transition from brushed to polished surfaces on the lugs, and the sharpness where the bezel meets the case band.
- Chronograph feel is the loudest tell. Pusher travel, the snap on reset, and the slight rattle of a 7750-derived clone are things photos never show.
- Dial printing and applied indices are the second tell. The edges of Arabic numerals should be crisp and evenly polished, not soft or rounded.
- Caseback engraving is where most copies stop trying. Reference stamping, serial fonts, and depth of engraving are usually off.
- Movement rate matters more than cosmetics. Clone movements typically drift well outside chronometer tolerances within months.
The legal and practical side in the US
Trafficking in counterfeit goods carries criminal penalties, and US Customs and Border Protection can seize counterfeit imports, including single pieces bought for personal use. Beyond the law, resale is close to impossible: no reputable dealer or platform will touch it, and any watchmaker asked to service it will know what it is within a minute. That resale value you were counting on does not exist.
Ways to get the look honestly
- Buy a genuine pre-owned Portugieser Chronograph. The 3714-series trades well below retail, and you get a serviceable watch with real value.
- Look at dress chronographs from brands that design their own cases and dials in the same 40 to 41 mm range. There are plenty under four figures.
- If the chronograph is the part you can live without, a clean three-hand dress watch gets you most of the visual effect for less money and less maintenance.
If you already own one
Do not list it as genuine. Disclose what it is, price it as what it is, and expect nothing. The cleaner move is to stop wearing it and put the money toward something you can hand down or trade.