Short answer
The reference IW371663 sits in IWC's Portugieser Chronograph line: a 41mm stainless steel watch with two counters, feuille hands, applied Arabic numerals, and a display back. Replica versions land in three tiers. A cheap quartz or basic automatic model at $80 to $150 looks fine from across a room. A $250 to $450 high grade copy gets the case profile, dial print, and crystal treatment close enough that you need the genuine watch beside it to spot the differences. Nothing at any price matches the in-house movement, the service network, or the resale value. If you are searching that exact number, you are looking at the 41mm chronograph case rather than the larger Classic, so confirm the exact dial and strap suffix against a reference database before comparing photos.
What the reference is
The Portugieser Chronograph is one of IWC's longest running designs, and the layout barely changes between generations: small seconds at 6 o'clock, a 30 minute totalizer at 12, and a central chronograph seconds hand inside a slim case with a box shaped crystal. Current watches in the 3716 range use the in-house calibre 69355 with roughly 68 hours of power reserve. Older 3714 era examples used a modified Valjoux 7750, which is why subdial spacing differs slightly between generations. Water resistance is rated at 3 bar, which in practice means splashes only. Dial colors across the range include blue, black, silver plated, and green, plus boutique editions, so two watches with almost identical numbers can look completely different.
What a good copy gets right
- Case profile: 41mm across, about 13mm thick, with a gentle lug curve that sits close to the wrist.
- Dial printing: thin, crisp numerals and the correct font weight on the brand name and the reference text.
- Hands: leaf shaped, mirror polished on the sides, with a clean bevel.
- Subdial position: small seconds at 6 and the counter at 12 should sit where they do on the genuine watch, not shifted by a millimeter.
- Crystal: box shaped, with anti reflective coating on the inside only.
- Caseback: engraved text, correct markings, and a sapphire window if the original has one.
Where most replicas fall short
- The movement. The small seconds at 6 layout forces makers to modify a 7750 style movement, and those modified versions are the ones that run poorly or fail. Ask what is inside before you pay.
- Thickness. Many copies run 1mm to 2mm thicker than the real thing, which changes how it sits under a shirt cuff.
- Applied numerals. Genuine markers are domed and polished. Cheap copies use flat stamped pieces.
- Strap and buckle. This is the first thing I swap. A decent leather strap and a signed buckle do more for the look than any other single upgrade.
- Finish. Check the transition between brushed and polished surfaces on the lugs. Blurry lines are the giveaway.
Movement tiers, plainly
Quartz: keeps time, wrong sweep on the seconds hand, thin case, cheap feel. Entry automatic, meaning a Miyota or a basic 7750 clone: reliable enough, but often no working chronograph and mushy pushers. High grade automatic, meaning a modified 7750 or a clone of the 69355: working chronograph, correct pusher feel, and the tier most buyers end up in. The catch is that seconds at 6 versions are the least reliable of the group, so budget for a service or a replacement movement down the road.
Six questions to ask before you pay
- Which movement is inside, and does the chronograph actually work?
- What are the measured diameter and thickness in millimeters?
- Can you send photos of the actual watch, including the caseback and clasp?
- Is the crystal coated inside, outside, or both?
- What is the return window, and who pays return shipping?
- How is it packed and shipped, and what happens if customs holds it?
Red flags
- Catalog renders instead of real photos.
- Claims of Swiss made or 1:1 Swiss movement at a price that cannot support it.
- No stated return policy.
- A seller who pushes you off platform and away from any payment record.
- Sites that reuse the same photos under five different reference numbers.
Living with it
Treat it as a watch, not an heirloom. Keep it out of the shower and the pool, since 3 bar means splashes. If you see a blue or purple sheen on the outside of the crystal, that coating will scratch off over time. Get it serviced when it starts losing more than a few seconds a day, and expect a watchmaker to charge the same labor rate as for any other automatic. Resale on a replica is close to zero, so buy one to wear.
Legal and practical notes
Replicas of this reference infringe IWC trademarks, and importing counterfeit goods into the United States is illegal. Shipments get seized and destroyed, and trafficking carries real penalties. Individual buyers rarely face charges, but the parcel is always at risk, which is one more reason to keep the spend modest and the expectations realistic. If you plan to have the watch serviced, tell the watchmaker what it is. Nobody enjoys finding that out halfway through a movement teardown.
Bottom line
My own rule is simple. If two listings differ by $80, take the one that answers your questions with clear photos of the watch in hand. Communication and documentation tell you more about what will arrive than any spec sheet does.