Short answer
A fake IW371776 is a replica of the IWC Portugieser Chronograph. The real reference is a steel watch with a 40.9 mm case, a calibre 79350 automatic chronograph movement, and a 44-hour power reserve. Replica listings run $150 to $600. The gaps show up in case thickness, dial print, subdial function, and movement finish.
What the reference is
The IW3717 group sits in the Portugieser line. IWC lists these specs for the series:
- Case: stainless steel, 40.9 mm diameter
- Movement: calibre 79350, automatic, chronograph with column wheel and vertical clutch architecture derived from the Valjoux 7750 base
- Power reserve: 44 hours
- Water resistance: 30 m (3 bar)
- Crystal: sapphire, antireflective coating on both faces
- Dial layout: running seconds at 6 o'clock, 30-minute totalizer at 12 o'clock
- US retail: about $8,000 to $8,500
The last two digits of the reference mark the dial, strap, or market variant. IWC does not publish a public decoder for each suffix, so confirm the exact configuration with an authorized dealer before you compare photos.
Where replicas differ
- Case thickness. Replicas built on an Asian 7750 base run 0.5 mm to 1.5 mm thicker than the real case. Ask for caliper photos.
- Dial print. The wordmark and minute track on copies show soft edges under 10x magnification. Genuine print has sharp borders.
- Subdial function. Cheap copies use a decorative 6 o'clock subdial. On the real watch it counts running seconds and it moves.
- Movement finish. Real 79350 movements carry Cotes de Geneve stripes, perlage, and a engraved rotor. Copies show rough edges and painted lettering.
- Caseback text. Reference numbers, serial numbers, and hallmarks are laser etched on the real watch. Copies use shallow stamps or pad printing.
- Pusher feel. The genuine chronograph pushers have short travel and a clean start and stop. Copies feel mushy.
Checks before you pay
- Ask for a photo of the caseback with the reference number visible.
- Ask for a photo of the movement through the caseback.
- Confirm the 6 o'clock subdial moves as a running seconds hand.
- Ask for the case diameter and thickness measured with calipers.
- Compare the lug shape and crown size with IWC catalog photos.
- Ask what movement the seller uses. Sellers who answer with a caliber name and jewel count are easier to check.
Price range
Replica Portugieser chronographs sell from about $150 for basic builds to $600 for higher grade builds with a modified 7750. A real IW371776 sells for about $8,000 new and $5,000 to $7,000 used, depending on condition and box and papers.
Legal status in the US
Trafficking in counterfeit goods violates 18 U.S.C. § 2320 and carries criminal penalties. US Customs and Border Protection can seize shipments of counterfeit watches at the border. Personal import of a counterfeit marked item is prohibited, and resale carries federal risk.