A replica IW371717 is worth buying when it copies three things: the 40.9 mm steel case, the subdial stack at 12 and 6, and a chronograph movement that feels like the Valjoux 7750 base the genuine watch uses. Miss any of those and you are paying for a logo on a generic chrono. The checklist below tells you what to inspect, in what order, so you can judge a replica from photos and a short video before money changes hands.
Reference points to compare against
The genuine IW371717 sits in the Portugieser Chronograph family. Keep these numbers in front of you while you review seller photos:
- Case diameter 40.9 mm, thickness roughly 12.3 mm, lug width 20 mm
- Stainless steel case, slim bezel, long straight lugs
- Chronograph minute counter at 12, small seconds at 6
- Date window at 3, no day function
- Sapphire crystal front and back, exhibition caseback
- Calibre 79350 family, 28,800 vph, about 44 hours of reserve
- Water resistance rated 30 m, which means splash resistance, nothing more
How to evaluate a replica IW371717
- Request a straight-on dial photo taken at eye level with no flash and a plain background.
- Measure the case across the bezel if the seller can use calipers, and reject anything under 40 mm or over 42 mm.
- Lay the photo next to a genuine reference image and check that the subdial centers sit on the vertical center line.
- Zoom on the date window and confirm it is cut at 3 o'clock with square corners and a font that matches the reference.
- Ask for a 20-second video that starts, stops, and resets the chronograph, then watch whether the minute counter at 12 snaps back to zero.
- Look at the caseback engraving under raking light, since shallow laser etching and crooked text are the fastest tells on this model.
- Check the brushing direction on the lugs and the polish on the bezel edge, because mixed finishes done badly show as smeared reflections.
- Confirm the strap, tang, and spring bars in the same video, then ask for a timestamped photo of the movement through the caseback.
Movement: the part most replicas get wrong
Most IW371717 replicas run an Asian 7750 clone. That is the correct architecture, and it gives you the right subdial spacing plus a working chronograph. The differences show up in the details: a rotor that spins with a cheap rattle, a pusher that needs a hard shove, and a reset that lands a hair off zero. A well-built example starts crisply, stops with a clean click, and returns both hands to twelve without hesitation. Ask the seller to film the reset three times in a row. Consistency across three resets tells you more than any spec sheet.
Price tiers
- Entry tier: thin plating, printed subdials, misaligned date, and a stamped clasp. Avoid.
- Mid tier: correct case size, applied markers, Asian 7750, decent brushing. Expect small tells at the date window and pusher feel.
- Top tier: correct thickness, crisp dial printing, good lume, engraved caseback, and a movement that has been regulated and cleaned.
Pay for dial and case accuracy first. Movement upgrades are easier to service later than a crooked date cut is to fix.
Red flags
- Photos taken at an angle that hides the date window or the subdial alignment
- Listings that quote a case size without a decimal point, such as 41 mm
- No video of the chronograph running
- Stock photos instead of the actual unit
- Sellers who refuse a caseback photo
Sizing and daily care
The 20 mm lug width takes standard straps, so plan for one leather strap for dress wear and one rubber or canvas strap for weekends. Keep the watch away from showers and swimming, since the 30 m rating on the caseback is a rating from the original design and replica gaskets are not tested to it. Wind a manual-wind 7750 gently, service the movement every four to five years, and store it off the crown.
Trade-offs to accept
A replica is not a genuine IWC. It carries no warranty from the manufacturer, holds no resale value, and cannot be serviced by an authorized watchmaker. Buy it because you want the look on your wrist, not because you expect an investment.