The fake IW371701 is a replica of the IWC Portuguese Chronograph, a 41 mm steel watch with a black dial, two subdials, and a Swiss chronograph movement. Replica makers copy the case and dial, then fit an Asian 7750 in place of the IWC caliber 79350. That single swap explains the price gap, the extra thickness, and most of the tells a buyer can catch in hand.
What Is the IWC IW371701?
IWC built the Portuguese Chronograph around a wide, clean dial and a two-register layout. The reference carries Arabic numerals, leaf-shaped hands, and a 30-minute counter at 12 o'clock with running seconds at 6. Case size sits near 41 mm across, and the watch ships on an alligator strap.
Inside, the genuine watch runs caliber 79350, a Valjoux 7750 base that IWC reworks with its own chronograph module, finishing, and regulation. Power reserve lands near 44 hours at 28,800 vibrations per hour. The result is a chronograph with a firm pusher feel and a smooth sweep on the 30-minute hand.
How a Fake IW371701 Differs From the Real One
Movement
Almost every replica uses the Asian 7750, a Chinese copy of the ETA/Valjoux 7750. It keeps the same two-register layout, so subdial positions line up with the real dial from across a table. The finish is the giveaway: rotor engraving looks stamped, perlage looks painted, and the balance sits under a plain bridge.
Case and Thickness
A 7750-based replica stacks taller than the original because the module sits higher in the case. Genuine thickness runs near 12.3 mm. Replicas land between 13.5 mm and 14.5 mm, and that shows under a shirt cuff or on a caliper.
Caseback engraving is the second soft spot. Letters lack depth, reference numbers use the wrong font, and the caseback rim often sits proud of the case edge.
Dial and Crystal
Dial printing splits the mid-tier fakes from the good ones. The "IWC" letters run thick, the subdial rings sit a touch wide, and the date window drifts off center. Sapphire with anti-reflective coating appears on better replicas, while cheap builds use mineral glass that flares under overhead light.
Replica Grades and Price Ranges
- Quartz, $60 to $120. Decorative subdials on many models, mineral glass, plated case, light weight in the hand.
- Asian 7750, $200 to $350. Working chronograph, steel case, decent dial print. Thickness and rotor finish give it away.
- Top tier, $400 to $700. Clone or genuine ETA 7750, sapphire crystal, tighter dial spacing, better strap. Still not a 79350.
How to Check a Fake IW371701 Before You Pay
- Ask for the movement name and a photo of the caseback with the rotor turned. A seller who dodges the question is hiding an Asian 7750.
- Measure thickness with calipers. Anything past 13.5 mm points to a 7750 build.
- Start the chronograph and watch the 30-minute hand. It should step forward and reset to zero at 12.
- Check the date at 3 o'clock for alignment and font weight against photos of the real dial.
- Look at the strap. Genuine alligator shows scale structure; most replicas ship embossed calf.
- Feel the crown. Winding should run smooth with no grit, and the date should flip at midnight.
Legal Position for US Buyers
Federal law targets sellers, importers, and traffickers, not the person who wears a replica at home. Trafficking in counterfeit goods is a crime under 18 U.S.C. section 2320. Customs can seize shipments at the border, and selling a fake as genuine is fraud in every state.
Frequently Asked Questions
Does the chronograph work on a fake IW371701?
On Asian 7750 builds, yes. The pushers start, stop, and reset the 30-minute counter at 12. Quartz replicas often have decorative subdials that follow the seconds hand and nothing more.
Is a fake IW371701 waterproof?
No. Treat any replica as splash-resistant at best. Gaskets are the first part a factory skips, and pressure testing a $250 watch costs more than the case is worth.
Which movement is the better choice?
A genuine ETA 7750 or a well-finished clone beats a stock Asian 7750 on accuracy and service life. Any watchmaker can service a 7750 platform, which keeps long-term ownership costs down.
How much should a good fake IW371701 cost?
Expect $300 to $500 for a replica with a working chronograph, sapphire crystal, and clean dial print. Below $150, corners get cut on the case, glass, and strap.
Can a jeweler tell it apart from the real watch in seconds?
Yes, in most cases. Thickness, rotor finish, and caseback engraving are visible without opening the watch or checking the serial.
Bottom Line
A fake IW371701 can look close on a wrist and pass at a distance. Open the caseback or measure the thickness and the illusion ends. Buy the movement you can service, not the logo on the dial.