A convincing IW371649 replica comes down to four checks: case size (41 mm wide, about 13 mm thick), the two-counter dial with chronograph minutes at 12 and running seconds at 6, crisp pusher action, and a chronograph seconds hand that starts and resets without a jump. Get those right and the rest is detail work. Get them wrong and no amount of polished finishing saves the watch.
What the genuine reference sets as the baseline
You cannot grade a copy without a fixed reference point. The current Portugieser Chronograph generation, which the IW371649 belongs to, gives you these anchors:
- Case: stainless steel, 41 mm diameter, roughly 13 mm thick, polished bezel with brushed flanks
- Dial: two subdials, elapsed minutes at 12 and running seconds at 6, no date window
- Movement: IWC calibre 69355, automatic chronograph, about 46 hours of power reserve
- Crystal: domed sapphire with antireflective coating on both faces
- Water resistance: 3 bar, marked on the caseback
- Strap: alligator leather on a folding clasp
Confirm the exact dial colour, hand shape, and printed text for IW371649 against official reference photos before you compare anything. Replica makers routinely mix parts from three or four references into one watch.
Counterfeit IW371649 Replica: Identification Guide
Prerequisites
- Digital calipers, accurate to 0.1 mm
- 10x loupe or a phone macro lens
- A phone with slow-motion video for the chronograph test
- Genuine reference photos printed or saved at a matching angle
- Bright, diffused light plus one raking light source
- Awareness of local law on buying, owning, and reselling replicas
How to inspect the watch, step by step
- Measure the case diameter across the bezel from 9 to 3 and record the number.
- Measure thickness at the centre of the caseback; anything past 13.5 mm sits wrong on the wrist.
- Measure lug width and confirm it matches the strap you intend to fit.
- Examine the dial print under the loupe: letter spacing, weight, and sharpness of every line.
- Check that each subdial hand reaches its minute track and that the counterweights match the reference shape.
- Start the chronograph and film the sweep in slow motion; a healthy movement beats at 28,800 vph, about eight steps per second.
- Reset the chronograph five times and confirm the seconds hand lands on zero every time.
- Press each pusher in turn; note grit, wobble, travel, and how firmly the spring returns.
- Wind and set the crown, then check engraving depth and that the stem engages cleanly in both positions.
- Run the raking light along the case flanks and bezel edge to expose waviness or uneven polishing.
- Inspect the caseback engraving for font, depth, and alignment.
- Weigh the head and compare against a published figure for the reference, not against a guess.
- Check lume application under UV for pooling or uneven coverage.
- Time the rate over 24 hours; plus or minus 15 seconds per day is realistic for a good clone.
Tells that expose a low-tier build
- A date window where the reference has none
- Subdials spaced too wide or too narrow against the genuine dial
- Printed text that bleeds or sits off-centre
- Chronograph seconds that stutter on start or overshoot on reset
- Flat applied numerals instead of faceted ones
- Pushers that thread or screw in, which the genuine does not
- Sapphire that shows a strong blue tint at an angle
Questions to put to the seller
- Which factory and which batch is this watch from?
- Can you send a slow-motion clip of the chronograph starting and resetting?
- Are the photos of the actual unit, not a stock set?
- What is the return window if the case measures outside tolerance?
Never treat a 3 bar rating on a replica as swimmable. The gaskets and caseback seating are the first things a clone factory skips, and water damage voids any return.