Short answer

A fake IW329073 copies an IWC Aquatimer Automatic 42. The genuine watch has a 42 mm steel case, 300 m water resistance, and IWC calibre 32111 with a 120-hour power reserve. Most fakes fail on three points: the dial print, the bezel action, and the movement. Check those first.

What the reference number means

IWC reference numbers start with four digits that mark the case family. The 3290 block covers the Aquatimer Automatic 42. The last digits mark dial, strap, or market variant. Counterfeiters reuse the full number on the caseback because buyers search for it.

IWC does not publish a public database of every variant photo. If the seller cannot show IWC service paper or a stamped warranty card, treat the number as unverified.

Dial and print checks

  • Logo: the IWC letters sit on one baseline. Fakes show uneven spacing or a thick C.
  • Date window: centered under the marker. Fakes sit low or high by a half millimeter.
  • Text: AUTOMATIC and 300m use thin strokes. Fakes use flat, heavy print.
  • Lume: applied in one layer. Fakes show overflow onto the dial.

Case and bezel checks

  1. Turn the inner rotating bezel. Genuine ones move with light drag and no rattle.
  2. Check crown threads. A rough first turn points to a copied case tube.
  3. Weigh the watch. A steel Aquatimer Automatic 42 head sits near 90 to 100 g on a rubber strap. Copies run 10 to 20 g lighter.
  4. Read the caseback engraving with a loupe. Fakes use shallow laser marks with rounded edges.

Movement

The calibre 32111 winds with a soft, even feel and hacks when you pull the crown. Copies often hold a Miyota 9015, a Seagull ST21, or an unmarked quartz hybrid. A watchmaker can open the case in minutes. Ask for a photo of the rotor and the balance bridge before you pay.

Price and papers

Genuine secondhand Aquatimer Automatic 42 pieces trade in the low four figures in US dollars. A listing far under that range is a warning sign, not a bargain. Serial numbers on the caseback and the warranty card should match.

If you already bought one

Stop the payment if you can. File a dispute with the platform. Ask a local watchmaker for a written assessment. IWC service centers can confirm authenticity, but they will not service counterfeit parts.