Short answer
The IW371681 is a reference in the IWC Portugieser Chronograph 41 mm line. Replicas sell for about $250 to $800. The genuine watch lists near $8,000 USD. Top-tier replicas copy the dial layout and case shape with skill. They miss on case thickness, subdial hand length, and the movement finish visible through the display back.
What the genuine watch is
- Case: steel, 41.0 mm wide, 13.1 mm thick
- Movement: IWC calibre 69355, automatic, 46 hour power reserve, 28,800 vph
- Dial: 30 minute counter at 12, small seconds at 6, date at 3
- Crystal: sapphire, front and back
- Water resistance: 3 bar
- Strap: alligator leather on a steel pin buckle
IWC uses many IW3716xx numbers in this family. The last digits carry the dial color and strap variant. Confirm dial color, case size, and strap in writing before payment. A seller who cannot name the variant is guessing at the number.
Where replicas hold up
Dial printing, applied markers, and leaf hands come close at the top tier. The case is a simple round shape with a polished bezel, and most factories cut it well. From a few feet away a good replica reads as a Portugieser.
Where replicas fail
Case thickness
Most replicas run a 7750 pattern movement. That movement sits taller than the 69355. Expect 14 mm to 15 mm against the real 13.1 mm. Measure the case with a caliper. Eye checks miss 2 mm.
Subdial hands
The small seconds hand at 6 should reach the printed track. Short hands that stop halfway across the subdial are the most common tell on cheap examples.
Movement finish
The display back shows the movement. Genuine 69355 has striped bridges, blued screws, and a deep engraved rotor. Replica bridges are stamped and the rotor engraving is shallow. Compare the font on the rotor text.
Chronograph feel
Start and stop should be firm with no creep. A 7750 based replica has a soft pusher and the seconds hand jumps when you start it.
Date window
Check the cut of the aperture and the weight of the date font. Replicas cut the window wide and print a light numeral.
Price tiers
- $150 to $300: quartz or low-grade automatic, wrong thickness, short subdial hands
- $300 to $500: 7750 automatic, correct dial layout, thin finishing
- $500 to $800: better case brushing, closer hands, sapphire front and back
Price tracks finishing and movement, not the reference number. Two sellers can list the same IW371681 at $280 and $700 and ship different watches.
Checklist before you buy
- Ask for a caliper photo of the case side.
- Ask for a macro shot of the subdial at 6.
- Ask for a photo of the case back with the movement in focus.
- Confirm the strap material and buckle type.
- Confirm the return window in writing.
- Pay by a method with a dispute process.
Limits of any replica
No replica carries an IWC warranty, and no factory publishes water resistance test data. Treat the watch as splash resistant at most. Service options are limited, since a local watchmaker may decline to work on a clone movement. Resale value is close to zero.