A fake IW371425 usually gives itself away in three places: the movement, the dial layout, and the caseback engraving. The genuine watch is an IWC Portugieser Chronograph from the 3714 family, and it runs calibre 79350, a Valjoux 7750 based automatic with subdials only at 12 and 6, no date window, and a 28,800 vph beat. If the watch you are holding has a date at 3 o'clock, a ticking quartz seconds hand, or three subdials, it is not a real IW371425.
What is the IW371425?
The IW371425 belongs to the Portugieser Chronograph line, a stainless steel reference with a round case of roughly 41 mm and a thin, dress-friendly profile. Inside sits calibre 79350, an automatic chronograph with a 30-minute counter and about 44 hours of power reserve. Water resistance is rated at 30 m, so the watch is splash resistant rather than a dive watch.
How do I check the dial on an IW371425?
The layout is the fastest visual test. A real Portugieser Chronograph is a bi-compax design: running seconds at 6 o'clock and the 30-minute counter at 12 o'clock, with nothing at 3 or 9 and no date aperture.
- Counterfeiters often drop in a stock 7750 layout, which pushes the running seconds to 9 o'clock and adds a date at 3.
- Subdial rings on a genuine dial carry fine concentric snailing, while copies show flat grey discs or printed rings.
- Leaf shaped hands should be polished, correctly sized, and aligned so the tip of the small seconds hand tracks the printed scale.
- Applied numerals sit proud of the dial with crisp, sharp edges. Fake markers look rounded, glued, or uneven in height.
- Printed text reads IWC and Schaffhausen in a tight, high resolution serif. On copies the letters blur, thicken, or drift out of alignment.
What does the movement reveal?
Calibre 79350 is a modified Valjoux 7750 that beats 8 times per second. A seconds hand that jumps once per second is quartz, and no genuine IW371425 is quartz.
Most 3714 family watches use a sapphire display back, so the movement is visible without opening the case. Look for Geneva stripes on the rotor and bridges, perlage on the base plate, blued screws, and crisp engraving of the calibre number and IWC branding. Cheap copies show stamped rotors, plastic movement rings, or no decoration at all.
Press the pushers. A healthy 79350 starts the chronograph with a firm click and resets instantly to zero. Mushy pushers, a slow reset, or a sweeping hand that stutters point to a low grade clone.
What do the case, crown and pushers tell you?
Genuine case finishing alternates polished and brushed surfaces with a hard, clean line between them. Lugs have sharp edges and even bevels, and the crown and pushers sit flush with the case band.
Turn the watch over. Caseback engraving on a real IW371425 is deep and evenly cut, showing the reference and a serial number. Fakes use shallow laser etching, and the serial rarely matches the warranty card or service papers.
Weight and thickness matter too. Copies are often a millimeter or more thicker and feel top heavy on the wrist.
Are the strap and buckle a giveaway?
IWC ships the Portugieser Chronograph on a stitched alligator or calf strap with a signed pin buckle or deployant clasp. Hardware should be heavy, polished, and marked. Counterfeit straps use stiff leather and thin, stamped buckles with soft engraving.
How do I verify an IW371425 without opening it?
- Photograph the movement through the display back on a plain surface at high magnification.
- Time the beat. 28,800 vph equals 8 beats per second, which a beat-rate app can confirm.
- Ask for the box, papers, warranty card, and service receipts, then match every serial number.
- Take the watch to an IWC boutique or authorized service center and pay for an authentication or service estimate.
Price is a signal too. An IW371425 offered far below the going market rate, with no papers and a rushed seller, deserves suspicion.
What if I already bought a fake?
Stop wearing it, gather the listing, messages, and payment records, and open a dispute with your payment provider. In the United States, counterfeit goods can be seized by customs and reselling them exposes you to legal liability.