A replica IW371645 is an unlicensed copy of an IWC Portugieser reference, not a watch built or authorized by IWC Schaffhausen. In the United States, making, importing, or selling counterfeit watches is illegal, and a buyer gets no manufacturer warranty, no service support, and no verification of the movement or materials inside the case. If you are researching this reference, the useful starting point is the genuine model and its real specifications, not the listing text written by a replica seller.

What the IW371645 reference actually is

IWC reference numbers do not follow an obvious public sequence, so the only dependable source for a specific number is IWC's own documentation. A check of the brand's official product pages will confirm the case size, movement family, dial variants, strap options, and whether the reference is still in production or has been superseded.

That matters because most descriptions of a "replica IW371645" online are copied between sellers. They repeat the same claims about case diameter, crystal type, and movement without quoting an authoritative source, and the details often drift from listing to listing.

How the replica market describes these watches

Sellers use a vocabulary that has no industry definition and no enforcement behind it.

• Grade labels. Terms like AAA, mirror grade, or super clone are marketing categories invented by sellers, not manufacturing standards.
• Swiss movement claims. A listing may claim a Swiss movement, but the buyer has no way to confirm the origin without opening the case, and doing so usually voids any return.
• Borrowed photos. Product images are frequently photographs of the genuine watch, not the item that ships.
• One-to-one claims. No copy matches a genuine reference at the level of finishing, tolerances, or component sourcing, because those come from the original supply chain.

The legal position in the United States

Trademark counterfeiting is addressed under the Lanham Act and under federal criminal law at 18 U.S.C. Section 2320, which covers trafficking in counterfeit goods. The practical consequences reach buyers as well as sellers.

• US Customs and Border Protection can detain, seize, and destroy counterfeit shipments, and the buyer generally loses the money paid.
• Marketplace listings for counterfeit goods are removed, and accounts tied to them are closed.
• Reselling a counterfeit watch as genuine exposes the seller to civil liability and, in serious cases, criminal charges.

The law treats a counterfeit as a trademark violation regardless of whether the buyer knew what they were purchasing.

Practical risks beyond the legal question

Ownership problems show up over time rather than on delivery day.

• Service. Independent watchmakers often decline to work on counterfeits, and parts for the cloned movement may not be available at all.
• Water resistance. Gaskets and case finishing determine whether a watch survives moisture. Unverified claims here lead to ruined movements.
• Materials. Plated finishes wear through, and coatings can release nickel, which is a known skin irritant.
• Resale. A counterfeit has no legitimate secondary market value.
• Payment risk. Many replica storefronts operate as fraud fronts and take payment methods with no buyer protection.

How to research a chronograph purchase honestly

If the goal is a well-made chronograph rather than the IWC name specifically, several reputable brands build comparable three-register designs at far lower prices, with warranties and service networks behind them. If the goal is the Portugieser look and feel, the pre-owned market for genuine IWC watches is active, and authorized dealers and established pre-owned platforms can verify authenticity, service history, and included box and papers.

Before buying any watch at this price level, ask for movement photographs, the serial number, and documented service records. A seller who cannot provide those for a genuine piece is not selling one.

If you already own a genuine IW371645

Keep the service record, avoid extended contact with moisture unless water resistance has been tested, and have the strap and gaskets checked at reasonable intervals. IWC can confirm a serial number and reference pairing, which protects you at resale.

Bottom line

The term "replica IW371645" describes a counterfeit, not a variant of the genuine watch. It carries legal exposure in the US, no warranty, no service path, and no resale value. Buyers who want the design should look at the genuine pre-owned market or at reputable alternatives rather than a listing that cannot be verified.