Short answer

The IW329045 is an IWC Aquatimer Automatic in a 42 mm steel case. Replicas run from about $200 to $800. The parts that separate a good one from a bad one are the movement, the internal dive bezel, the dial print, and the case size. A replica is not a dive watch. Treat water resistance as zero until a watchmaker tests it.

The genuine watch

IWC lists the IW329045 in the Aquatimer Automatic line. Case: steel, 42 mm across, about 14 mm thick. Crystal: domed sapphire. Water resistance: 300 m on the genuine watch. Movement: caliber 30120, automatic, 28,800 vibrations per hour, about 42 hours of power reserve. Date at 3 o'clock. The dive bezel sits under the crystal and is driven by a crown on the case band, not by a friction ring on the outside of the case.

Confirm the dial color and the bracelet or strap variant with the seller before paying. The reference family covers more than one finish, and replica sellers mix parts between versions.

Movement: the main split

Low-tier builds use a Seiko NH35 or a Chinese automatic. Mid-tier builds use a Miyota 9015. Top-tier builds use a clone of an ETA 2892 or a decorated movement stamped to look like the 30120.

  • NH35: 21,600 vph, no decoration, rotor spins loud.
  • Miyota 9015: 28,800 vph, hacking, thin, reliable parts supply.
  • Clone 2892: 28,800 vph, closest to the genuine gear train.

Ask for a photo of the movement and the rotor engraving. A timegrapher app on a phone will show the beat rate in seconds.

Case and bezel checks

  • Measure the case with calipers. It should read 42 mm without the crown. Many fakes run 43 to 44 mm.
  • Turn the bezel crown through a full rotation. It should index in 60 steps and stop with a firm click.
  • Look at the gap between the bezel ring and the case. A wide gap points to loose machining.
  • Check the crown threads. Gritty threads are common on cheap builds and they wear out first.

Dial and print

Check three things at arm's length and then under a loupe: the height of the applied markers, the sharpness of the date window edge, and the lume fill. Markers on a good replica sit flush with even lume. On a weak one the lume sits above the metal ring or spills onto the dial. The date font should match the genuine print, with a flat top on the 4 and a straight leg on the 1.

Water resistance

Assume no sealing until proven. Ask the seller for a pressure test result and the date it was run. If there is no paper, pay a local watchmaker $30 to $60 for a test and new gaskets. Most replica cases pass 3 bar and fail at 10 bar. Do not swim with the watch until it has been tested.

Price bands

  1. Under $200: NH35 or quartz, printed markers, thin case back.
  2. $250 to $450: Miyota 9015, correct 42 mm case, mixed dial quality.
  3. $500 to $800: clone 2892, sapphire with anti-reflective coating, smoother bezel action.

Questions for the seller

  • Which movement, and can you send a photo of the rotor and balance?
  • What is the case diameter measured with calipers?
  • Was the watch pressure tested, and on what date?
  • What is the return window, and who pays return shipping?
  • Is the bracelet solid link or folded, and does it taper?

Legal note

In the US, trafficking in counterfeit goods is a federal crime under 18 U.S.C. 2320. Customs can seize a replica shipment. The watch is not an IWC and carries no IWC warranty or service support.