If you are shopping for a fake IW371497, the most useful rule is to compare the replica against the genuine reference on paper before you compare it in photos. The IW371497 belongs to the IWC Portugieser Chronograph family, so any honest copy should match the same basic architecture: a case close to 41 mm, a two register chronograph dial with the counters stacked vertically at 12 and 6, a date window at 3, and a slim leaf shaped handset. A listing that shows three subdials, a date at 4:30, or a quartz movement is not a copy of this reference, it is a different watch wearing an IWC name. Decide which matters more to you, correct case shape and dial layout or a mechanical movement, and let that priority filter the listings before you spend anything.
What the reference number tells you
IWC organizes the Portugieser Chronograph into reference families rather than one off numbers. The 3714 family covers the long running 40.9 mm version that used a modified Valjoux 7750 base calibre, and the 3716 family covers the later 41 mm version with the in house 69355 calibre. The IW371497 code sits inside that lineage. Treat any seller who describes the watch as something else entirely with caution. Ask three questions: what is the case diameter, what is the subdial layout, and what movement family is inside. A seller who cannot answer all three is describing a stock photo, not a watch.
What to look for
Case and proportions
- Diameter should land near 40.9 to 41 mm, measured across the case without the crown.
- Thickness near 12.3 to 13.1 mm. A very thin case usually means a quartz module inside.
- Lug width near 20 mm, which keeps standard Portugieser straps usable.
- A polished bezel against brushed case flanks, with a crisp line between the two finishes.
- Water resistance quoted at 3 bar on the genuine watch. Be skeptical of replica listings claiming 100 m or more.
Dial
- Two counters only, at 12 and 6, on the same vertical axis as the crown. The 12 o'clock counter is chronograph minutes, the 6 o'clock counter is running seconds.
- Applied numerals and indices. Cheap copies print the markers flat on the dial and they catch light differently.
- Leaf hands, thin with a soft taper, not baton or syringe shapes.
- Date at 3 with a disc that matches the dial color, and a window sized to the numeral height.
- Printing that is level, sharp, and even in stroke weight across the whole dial.
Movement
Most chronograph copies of this watch run a Chinese clone of the Valjoux 7750, and a smaller number run quartz. The 7750 layout is what makes the 12 and 6 counter positions possible, so a watch with the correct layout almost certainly has a 7750 type movement. Check the small seconds hand at 6. A mechanical movement advances it several times per second, while a quartz ticks once per second with a visible jump. The genuine calibres run at 28,800 vibrations per hour and offer roughly 44 to 46 hours of power reserve, so a pusher feel that is gritty or a chronograph that resets slowly points to a lower grade module.
Crystal, case back, and strap
- Sapphire crystal with anti reflective coating on both faces. Mineral glass shows more glare and scratches sooner.
- Case back engraving that is centered, deep, and evenly spaced. Crooked or shallow text is a common shortcut.
- Alligator grain leather with even stitching and a signed deployant or pin buckle.
Numbers worth memorizing
- Case diameter: 40.9 to 41 mm
- Case thickness: 12.3 to 13.1 mm
- Lug width: 20 mm
- Frequency: 28,800 vph, or 8 beats per second
- Water resistance on the genuine watch: 3 bar
Common pitfalls
- Wrong subdial layout. Three register dials are the most frequent mismatch on this reference.
- Quartz movements sold as automatic. Ask for a movement photo with the case back removed.
- Printed markers instead of applied metal. This shows up fastest in low light.
- Date fonts and window sizes that do not match the genuine dial.
- Listings that never show the case back, the clasp, or the movement.
- Stock imagery only. Ask for photos of the actual piece with a dated note in frame.
Legal and practical notes
Counterfeit watches infringe trademarks, and in the United States both selling and importing them can lead to seizure and civil liability. U.S. Customs and Border Protection can hold or destroy shipments of infringing goods, and enforcement does not require the brand to open a case first. A replica also carries no manufacturer warranty, no authorized service network, and effectively no resale market. If the design is what draws you rather than the name on the dial, an unbranded or licensed homage gets you the same proportions without the legal exposure.
FAQ
Is a fake IW371497 worth buying?
It depends on what you want from it. If you want the Portugieser look on a small budget and accept that service and resale are not part of the deal, a well made copy can serve that purpose. If accuracy, longevity, and resale value matter, save for the genuine watch or choose an honest homage instead.
How do I separate a good replica from a poor one?
Work in order: case proportions first, then dial layout, then movement type, then finishing details. Most bad copies fail at step one or two, which saves you from inspecting fonts on a watch that was never the right shape.
Do replicas use the same movement as the genuine watch?
No. Genuine Portugieser Chronographs use IWC calibres, one of them based on the Valjoux 7750. Copies use clones of that design, generic chronograph modules, or quartz. The layout can look identical while the internals are entirely different.
What wrist size does this case suit?
A 41 mm case on 20 mm lugs generally suits wrists from about 6.5 to 8 inches. Ask for the lug to lug measurement and compare it to the flat width of your wrist, because that figure decides comfort more than diameter does.