Short answer
The replica IW371681 is a counterfeit of the IWC Portugieser Chronograph, a 41 mm stainless steel watch with a blue dial and the in-house calibre 69355. Copies fall into three rough tiers: quartz lookalikes, mid-tier automatics built on a Valjoux 7750 base, and super clone builds that copy the case geometry and dial layout. Judging one comes down to measured dimensions, dial print, subdial function, crown feel, and the movement visible through the back. Counterfeits are illegal to import into the United States.
Genuine baseline specs
Use the real watch as your measuring stick.
- Case: stainless steel, about 41 mm across, about 13.1 mm thick
- Dial: blue sunray finish, subdials at 12 and 6, date window inside the 6 o'clock subdial
- Movement: calibre 69355 automatic, column wheel chronograph, 46 hour power reserve, 28,800 vph
- Crystal: domed sapphire with anti-reflective coating on both faces, sapphire caseback
- Water resistance: 3 bar, meaning splash protection only
- Strap: 20 mm lug width, alligator leather or steel bracelet
Before you start
- Calipers or a digital ruler
- A 10x loupe or a macro lens
- Reference photos of the genuine reference from more than one angle
- A timer to watch the chronograph for ten minutes
How to check a replica IW371681
- Measure the case across the 9 to 3 line without the crown. Anything clearly over 41 mm is a mismatch. Measure thickness too, since 7750-based builds often sit near 15 mm.
- Measure the lug width. It should read 20 mm. Replicas that take a 22 mm strap are built on a different case.
- Set the chronograph running and watch which subdial moves. The 30 minute counter belongs at 12. The 6 o'clock subdial is running seconds, and the date sits inside it. A build where the 6 o'clock subdial sweeps as the chronograph second hand uses a different movement layout.
- Inspect the dial print under magnification. Look at the wordmark, the town name, and the Automatic line. Blurry or heavy printing is the most common giveaway.
- Check the hand shapes. The Portugieser uses feuille, or leaf, hands. Look for a clean taper and a polished or blued finish without tool marks.
- Press the pushers. Start, stop, and reset should feel distinct. A reset that snaps hard or a pusher that grinds points to a low-grade chronograph module.
- Pull the crown and set the time and date. The date should flip near midnight, not mid-afternoon.
- Look at the caseback. The genuine calibre 69355 shows a specific bridge shape and a signed rotor. Replicas often show a decorated 7750 or a printed plate.
- Tilt the crystal toward a light. Genuine sapphire has a faint blue tint from coating on both faces. Uncoated or heavily tinted glass is a downgrade.
- Weigh the head on a kitchen scale. A steel case in this size lands roughly in the 70 to 90 gram range depending on the strap or bracelet.
Common red flags
- Listings that describe the movement only as imported or high grade
- Photos of the dial only, with no caseback or side profile
- Case thickness over 14 mm
- Date at 3 o'clock
- Sapphire claimed, but the crystal flexes when pressed
- No video of the chronograph running
Legal and practical limits
Trafficking in counterfeit goods is a criminal offense under 18 U.S.C. 2320, and U.S. Customs and Border Protection can seize and destroy counterfeit watches at the border. Buyers have lost shipments and, in some cases, faced civil penalties. A replica also carries no warranty, no service network, and no resale value. If the goal is the look of a Portugieser Chronograph on a budget, a known homage brand avoids the fake trademark and can still be serviced. That trade-off is worth weighing before you buy a copy.