The replica IW371790 is a copy of the IWC Portugieser Chronograph, a 41 mm steel chronograph with a vertical bi-compax dial and an in-house automatic movement in the genuine version. Replica quality for this reference splits into clear tiers, and the gaps show up in four places: case thickness, dial printing and applied markers, pusher feel, and the movement inside. Use the steps below to sort a good example from a bad one before you pay.
Before you shop
- Pin down the genuine reference you want copied, including dial color, strap type, and case metal.
- Ask the seller for a photo set and a short video, not a stock image.
- Keep calipers and a kitchen scale on hand for the watch when it arrives.
How to inspect a replica IW371790
- Request six photos before purchase: dial straight on, dial at an angle, both case flanks, caseback, clasp, and a macro of the dial text. Walk away from any seller who sends catalog images only.
- Measure the case with calipers. The genuine case runs 41 mm across and about 13 mm thick. A replica that measures 43 mm or wears like a brick is a lower tier build.
- Check the dial layout. The subdials should sit at 12 and 6 with even spacing from the center, and the hands should line up with the printed track at every hour.
- Study the markers with a loupe. Applied metal markers catch light and cast a small shadow. Painted or glued markers sit flat and read dull.
- Read the dial text. The logo, the brand name, the city name, and the word automatic should match the reference in font, weight, and spacing. Crooked or spread out text is the most common flaw on this model.
- Press both pushers. A 7750-based replica feels slightly gritty, while a well-built clone should start, stop, and reset with a firm click and send the chronograph hand back to zero in one motion.
- Wind the crown and watch the small seconds. If that hand ticks once per second, the watch holds a quartz movement. That is a dealbreaker at replica prices.
- Flip the watch over and inspect the caseback. Engraving should be cut into the metal, not printed on the surface, and the reference and serial numbers should stay crisp under a 10x loupe.
- Weigh the watch on a kitchen scale. A steel chronograph on a leather strap usually lands between 80 and 100 grams. Anything far below that points to a hollow case or a thin bracelet.
- Inspect the strap and clasp. Stitching should be even and tight, the leather should smell like leather, and the deployant should close without a rattle.
- Skip water testing unless the seller states a rating you can verify. Never swim with a replica, no matter what the listing claims.
Red flags
- Subdial spacing that crowds the center pinion or overlaps the printed track.
- A date window with the wrong font, or a magnifier that sits off-center.
- A rotor that rattles when you shake the watch near your ear.
- Photos that hide the crown side or the caseback.
- A price far below the tier you are shopping in. Cheap usually means a quartz movement and a plated case.
What each tier buys
Entry replicas use a plated case, a printed dial, and a quartz or low-grade automatic movement. Mid tier adds a solid steel case, applied markers, and a clone 7750. The top tier copies case thickness, dial text, and hand shape close to the genuine piece and runs a decorated automatic movement with a working chronograph. Ask the seller which tier a listing belongs to, then compare that answer to the photos.
Care after purchase
Keep the watch away from steam and hot water. Wipe the case and crystal with a microfiber cloth, and store it on a soft surface so the deployant does not scratch the caseback. Have the movement serviced every three to five years if you wear the watch often, and replace the strap once the stitching starts to fray.