Short answer

A replica IW329136 is a counterfeit copy of an IWC Aquatimer Automatic 42 from the 3291 case family. Replica market prices run about $200 to $600. The copy reproduces case shape, dial layout, and strap. It does not use an IWC movement, does not carry a factory pressure test, and has no IWC warranty or service support.

What the reference number means

IWC splits its reference codes. The first four digits name the case family. The last two digits name the dial, strap, and market variant. 3291 is the Aquatimer Automatic 42. Shared traits across the family: a 42 mm case, an inner dive scale, a rotating bezel ring on the outside of the case, a screw-down crown, and a rubber strap or steel bracelet.

IWC lists 300 m water resistance for Aquatimer Automatic models. Movement data changes by production year, so confirm specs from the catalog for the variant you plan to compare against. Dial color and strap change between sub-references too.

What the copy matches

  • Case diameter and lug width, when the seller lists both
  • Dial printing, marker shape, and date window position
  • Bezel function, an outer ring that drives an inner dive scale
  • Sapphire or mineral crystal, depending on tier
  • Strap style and buckle shape

What differs

  • Movement. Genuine IWC calibres come from IWC. Replicas use a Seiko NH35, Miyota 9015, ST2130, or an ETA 2824 clone.
  • Case finishing. Brushed and polished transitions on replicas show wider gaps and softer edges.
  • Water resistance. Sellers quote 300 m. Most replicas are not pressure tested, and gaskets may not seal past splashes.
  • Lume. Replica lume glows for minutes. Super-LumiNova glows for hours.
  • Caseback engraving. Font weight and depth differ from the factory stamp.
  • Bezel action. Clicks feel loose or gritty.

Price tiers

  1. $150 to $250. Quartz or a low-grade automatic, mineral glass, stamped clasp.
  2. $250 to $450. NH35 or 2824 clone, sapphire crystal, decent case finish.
  3. $450 to $700. Decorated rotor, closer dial print, better bracelet. Still not a genuine watch.

Checks before you pay

  1. Ask for caliper photos. Case diameter, thickness, and lug width.
  2. Request a movement photo with the caseback removed.
  3. Test the crown. It should thread in with light pressure and no cross-threading.
  4. Test the bezel. Count the clicks and check for back play.
  5. Charge the lume with a light, then check it in a dark room after 30 minutes.
  6. Check the date flip. It should change within 10 minutes of midnight.

Movement options in the replica market

Seiko NH35: about 41 hours of power reserve, hacking, hand winding. Miyota 9015: about 42 hours, 24 jewels, thinner than the NH35. ETA 2824-2 and its clones: about 38 hours. A decorated rotor does not change the base movement.

Service and parts

IWC will not service a counterfeit. Independent watchmakers can replace gaskets and movements. Parts come from the same channels that supply the case makers. Expect $80 to $150 for a movement swap and $30 to $60 for a gasket and seal job.

Legal status in the US

US law bans trafficking in counterfeit goods, and US Customs and Border Protection can seize shipments. Buying for personal use carries lower risk than resale, but the item can still be seized.

Bottom line

A replica IW329136 gives the look of an IWC Aquatimer Automatic 42 at 5 to 10 percent of the genuine price. It does not give the movement, the pressure test, or the service network. Compare case size and bezel function first. Those two items decide whether the watch fits and works.