The short answer

IW371479 is an IWC Schaffhausen reference number that belongs to the Portugieser family, the 3714 line of two-register chronographs. It is not a Rolex reference, and it is not a stand-alone model with its own name. That matters because most pages ranking for this term are counterfeit storefronts recycling a reference number they never verified. I am not going to write a sourcing guide for a counterfeit version of it. What I can do is explain what the reference is, how counterfeit copies of this line tend to fail, and what legal options exist if you want the look.

What the reference points to

The Portugieser Chronograph is defined by a clean dial with two sub-registers, running seconds at 6 o'clock and elapsed minutes at 12, applied numerals, feuille hands, and a slim bezel that leaves a wide dial opening. The 3714 generation is commonly cited as using an IWC-modified Valjoux 7750 base, which is why the case is thicker than the dial suggests. Exact case dimensions, dial variants, and production years vary by reference, so treat any spec sheet you read online as a lead to confirm against IWC's own listing rather than a fact.

Why counterfeit guides for this reference are unreliable

• The reference number is often wrong. Sellers attach IW371479 to cases that do not match the dial layout or sub-register positions of the actual line.
• Movement claims are unverifiable. A counterfeit has no service network, no parts supply, and no repair path if the chronograph module fails.
• Described materials rarely match delivered materials. Case finishing, crystal coating, and dial printing are the usual gaps.
• Import risk is real. Counterfeit goods are subject to seizure by U.S. Customs and Border Protection, and trafficking in counterfeit goods is a federal offense.
• Resale value is zero. There is no secondary market for counterfeit watches, in part because selling one is itself unlawful.

Legal ways to get close to the look

• Buy the genuine reference pre-owned. The 3714 line has traded for years, so examples with service history exist through established dealers.
• Look at homages that use their own name and their own case design, rather than a copied logo.
• Consider a different genuine chronograph at a lower price point if the dial layout is what you actually want.
• If you already own a genuine example, get it serviced by IWC or a watchmaker with documented parts access, and keep the paperwork.

Use case

If you want a two-register chronograph on a leather strap and you care about serviceability, buy genuine or buy an honest homage. If you want a specific reference number to hold value, only the real one does that.