Short answer
A fake IW371761 is a replica of the IWC chronograph that carries a 3717-family reference number. The market sells at least three versions: a quartz knockoff, a mid-grade automatic with coarse finishing, and a high-grade replica built to match the original case and dial. Price and listing photos decide nothing on their own. The movement tier, the crystal, and the case finishing decide what you actually receive.
What the genuine watch is
The 3717 reference belongs to the IWC Pilot's Watch Chronograph line. The watch uses a stainless steel case of about 42 mm, a soft-iron inner shield for magnetic protection, a convex sapphire crystal with an anti-reflective coating, and IWC caliber 79320, a reworked Valjoux 7750. The dial carries running seconds at 9 o'clock, chronograph minutes at 12, chronograph hours at 6, and a day-date window at 3. A replica that shifts those positions, drops the day function, or flattens the crystal has failed at the layout stage.
What to have ready
- A photo of the genuine 3717 dial and caseback for side-by-side comparison.
- A digital caliper or a ruler with millimeter marks to confirm the case size on arrival.
- A dark room or a closet for the lume test.
How to inspect a replica IW371761 before you pay
- Ask the seller for the case diameter in millimeters and compare it with the roughly 42 mm original. A 40 mm or 44 mm claim tells you the case is a generic part.
- Request a straight-on dial photo and check that the running seconds sit at 9 o'clock, not at 6 where cheap 7750 conversions place them.
- Confirm the day and date both change at midnight. Low-tier copies often print a fixed day disc that never moves.
- Ask which movement is inside. A Seagull ST19, an Asian 7750, and a quartz module each behave, sound, and service in different ways.
- Request a side profile photo to judge crystal height. A domed sapphire that rises above the bezel matches the original; flat mineral glass does not.
- Ask for a close photo of the caseback engraving, then check letter spacing, font weight, and the reference number format.
- Ask for a lume photo shot in a dark room. Weak or uneven glow points to a dial made without real lume.
- Ask what the seller does if the chronograph arrives stopped or the date window sits off-center. A written return window is the only useful answer.
Movement tiers and what they cost you
- Quartz: cheapest option, no sweeping seconds hand, and subdials that are often decorative rather than functional.
- Asian 7750: correct subdial layout and a working chronograph, but rotor noise and rough pusher feel are common.
- Swiss ETA 7750 or a well-finished clone: closest to the original 79320 behavior and the only tier worth servicing.
Price expectations
Quartz copies sit at the bottom of the market. Mid-tier automatics with a working 7750 layout cost several times more, and high-grade replicas with sapphire glass, correct lume, and a decorated movement cost more again. If a seller quotes a high-grade price and cannot show a movement photo, treat the listing as mid-tier at best.
Before you buy
A replica stays a replica. It carries no IWC warranty, holds little resale value, and cannot be sold as genuine. Buy it as a look-alike, price it as a look-alike, and judge the seller on answers to the questions above rather than on the photos in the listing.