Quick answer
A fake IW3716 is a counterfeit of the IWC Portugieser Chronograph. IWC sells the real watch with an in-house calibre 69355 under a sapphire display back and a steel case listed at 41 mm. Counterfeits use ETA 7750 clones, Chinese chronograph movements, or quartz, and they often hide the movement behind a closed caseback or a stock photo. Price is the first filter. A real steel Portugieser Chronograph starts near USD 7,000 at retail. A listing at USD 150 to 500 is not a genuine watch.
What the reference number means
IWC uses a five-digit block after the prefix, so a genuine watch reads IW3716 followed by two more digits, for example IW371604 or IW371609. That string sits between the lower lugs. Counterfeit cases often carry the wrong block, a laser-etched string, or no engraving at all.
Movement is the main check
Calibre 69355 is an automatic chronograph with a column wheel, running at 4 Hz, or 28,800 vibrations per hour. The ref. 3716 shows it through a sapphire back. Look for the balance, the column wheel, and the rotor engraving. Fakes show a decorated ETA or Valjoux 7750, a Seagull ST19, or a rotor with the wrong font. Ask for a movement photo before payment.
Dial and case checks
- Numerals and indices are applied, not painted. The metal has polished edges.
- Leaf hands are bevelled and reach the printed track.
- Subdial layout is a 30-minute counter at 12 and small seconds at 6.
- Case thickness sits near 13 mm. Copies run thicker and feel top heavy.
- Crown engraving is deep and sharp. Copies show a shallow stamp.
- Crystal is sapphire with coating on both faces, so it shows a faint blue tint under some light.
Price and listing signals
Retail for steel versions sits near USD 7,000 to 8,500 depending on reference and year. Used examples trade lower. Red flags on a listing include stock photos, no caseback image, no movement image, no serial photo, a seller who takes crypto only, and a price far below market. The same workshops in Guangzhou and Shenzhen that build Rolex replicas also build IWC replicas, and the same storefronts list IWC, Panerai, Omega, and Rolex side by side.
What is not public
IWC does not publish production numbers or serial ranges by reference. A definitive check on one watch needs an IWC service center or a trained watchmaker with the case in hand.