What a fake IW376045 is
A fake IW376045 is a counterfeit watch built to pass as that IWC reference. Most examples pair a generic chronograph movement with a copied steel case, reprinted dial text, and an engraved caseback. The dial is often the best-finished part of the fake, so dial printing by itself will not settle the question. The movement, the caseback engraving, and the feel of the pushers decide it.
No single check proves a watch is genuine. Work through the steps below in order, and treat two or more failures as a reason to walk away.
Prerequisites
- A 10x loupe and a bright, diffused light source
- Digital calipers for case diameter, thickness, and lug width
- The official IWC specification for the reference, showing case size, caliber number, and dial layout
- A watchmaker who can open the caseback and read the movement
Authentication steps
- Write the reference number down as it appears on the papers, then check it in the official IWC reference database. Confirm the number exists, the case size matches your caliper reading, and the dial layout matches the catalog photo.
- Measure the case thickness at the center of the caseback. Counterfeit cases run 0.5 to 1.5 mm thicker because the copied movement sits taller than the original.
- Inspect the caseback engraving with the loupe. Genuine IWC engraving has sharp, even edges and consistent depth. Laser-etched fakes look shallow, blurry, or uneven at the serifs.
- Compare the reference and serial numbers on the caseback with the warranty card and any IWC service record.
- Have the watchmaker open the caseback and identify the movement by caliber number rather than by appearance.
- Study the dial print at 10x magnification. Check the numeral shapes, the thickness of the minute track, and the alignment of the date window inside its aperture.
- Run the chronograph. Start, stop, and reset it several times. Genuine pushers have a firm, short travel. Fakes feel soft, gritty, or slow to return.
- Turn the crown and bezel. A genuine screw-down crown seats in about two and a half turns and moves without catching.
- Examine the bracelet links, end links, and clasp stamps. Genuine clasps show crisp stamping and an even fold with no side play.
- Weigh the watch on a kitchen scale and compare it to the published weight for that case material.
Box, papers, and seller
Original packaging helps but does not authenticate a watch. Fakes ship in convincing boxes all the time. Focus on the warranty card number, the country code, and the date stamp. A seller who refuses an in-person inspection by a watchmaker, avoids video calls, or pushes a bank transfer with no refund terms is a bigger warning sign than any box.
Price as a filter
Compare the asking price to recent sold listings for the same reference in the same condition, not to retail. A price far under the market range for a steel IWC chronograph is a filter, not a bargain signal. Ask why the price is low and listen to the answer.
After you find a fake
Stop the payment if you still can. Photograph the watch, the caseback, and the listing before you return it. Report the seller through the platform where you found the watch, and file a chargeback with your card issuer if the seller stalls. If you already own the watch, have a watchmaker document the movement in writing before you decide what to do with it.