A fake IW371475 is a copy of the IWC Portugieser Chronograph, and the fastest way to identify one is to compare four things against a genuine reference: dial printing crispness, subdial spacing, caseback engraving depth, and the movement visible through the display back. Entry-level replicas fail on at least two of those four points. Higher-grade replicas pass a casual glance but still drift on font weight, date wheel alignment, and crown threading.

What Is the IW371475?

The IW371475 sits inside the IWC Portugieser Chronograph family, a line built around a 40.9 mm stainless steel case, a sapphire crystal, and a two-register chronograph layout with subdials at 12 and 6 o'clock. The prefix "IW3714" identifies the model family, while the final digits encode dial finish, strap choice, and market variation. That is why two watches can look nearly identical yet carry different reference numbers.

Inside, the family traditionally uses calibre 79350, a Valjoux 7750 base reworked by IWC with a slower beat rate and a decorated finish. Water resistance is rated at 30 meters, which is splash protection rather than swimming depth. Knowing those specs gives you a checklist before you ever look at a dial.

How Do You Spot a Fake IW371475?

Dial and printing

Genuine IWC printing is applied with sharp edges and consistent stroke width, and the script signature sits level with no bleed into the lacquer. Fakes usually show thicker numerals, a blurry manufacturer line, and subdial rings spaced too close to the center or too far out. Under a loupe, the gap between an etched dial and a stamped dial is obvious.

Case, crown, and pushers

Check the crown threading and the pusher travel. Genuine chronograph pushers give a short, positive click, while cheap replicas feel mushy or grind on the return stroke. Lug brushing should run in one direction, and the case flanks should feel uniformly polished with no soft edges.

Caseback engraving

Reference numbers, serial numbers, and the logo are engraved with crisp vertical walls, not laser-etched haze. Look at the spacing between the reference and the serial, since fakes often misalign the two or use a font one weight too heavy. A serial number that repeats across listings is a hard stop.

Movement

A display back makes the movement the strongest test. Real calibre 79350 shows Geneva stripes, blued screws, and a signed rotor, while replicas typically show a generic chronograph module with a printed rotor plate and no perlage. If the balance wheel ticks at a visibly fast rate, the movement is not a 28,800 vph calibre.

What Do Replica Grades Mean?

Entry replicas use quartz or a low-grade automatic and cost very little, and mid-tier builds copy the exterior well while keeping the wrong movement. Top-tier builds replicate the case, dial, and crystal closely and sometimes accept a genuine-spec movement. Price tracks dial accuracy and movement quality, not the name printed on the rotor.

What Should You Verify Before Buying?

• Ask for macro photos of the dial at 12 and 6 o'clock, plus the caseback engraving.
• Request a movement photo or a timing reading if the watch has a display back.
• Confirm case thickness, because thin copies of a 12 mm watch are common.
• Check whether the seller accepts returns and how the watch ships.

Is a Fake IW371475 Worth Buying?

It depends on what you want from the watch. If dial and case accuracy matter most, a top-tier build gets you close at a fraction of the genuine price. If you need serviceability, resale value, or warranty coverage, only the genuine reference delivers those.