Short answer

A fake IW328070 is a counterfeit watch that carries IWC markings and that reference number. IWC stamps reference numbers on the caseback in the form IW plus six digits. The IW3280xx block covers Pilot's Watch Mark series models. Public IWC catalog data for IW328070 could not be confirmed for this guide, so a listing that uses that number needs a check against IWC spec sheets before money changes hands.

What the reference tells you

IWC reference numbers start with IW and end with six digits. The first digits group the model family. IW3280xx sits in the Pilot's Watch Mark line. A reference number alone does not prove a watch is real. Counterfeiters copy numbers from real listings and print them on copies.

Checks that separate a real watch from a copy

Caseback engraving

Real IWC casebacks carry the reference number, a serial number, and the brand name. The engraving is laser cut. Edges look sharp under a 10x loupe. On copies the letters look rounded, shallow, or filled with paint.

Movement

IWC Mark XX watches use the in-house caliber 32111 with a 120-hour power reserve. The rotor is engraved and the bridges show Geneva stripes. Copies use ETA or Sellita clones, or Chinese movements, with a 38 to 42 hour reserve. A three-day power reserve test shows the gap.

Case and crystal

Mark XX cases measure 40 mm across and 10.8 mm thick, with a 20 mm lug width. Measure with calipers. The sapphire crystal has antireflective coating on both faces. Copies use mineral glass or coat one side only.

Weight

A steel Mark XX on a bracelet weighs about 150 g. Copies run 20 g to 40 g lighter because the case walls and bracelet links are thinner.

Price and papers

IWC lists Mark XX models at retail prices between $5,000 and $7,000, depending on strap or bracelet. Listings near $500 are copies. Genuine watches ship with a warranty card and can be registered for an 8-year warranty.

Terms sellers use

Sellers use "replica", "clone", "super clone", and "1:1". All of these describe a watch not made by IWC. No grade changes that fact.

Open points

IWC catalog data for IW328070 could not be confirmed. Case sizes, calibers, and prices above come from IWC pages for Mark XX models in the same reference block. Check the number on the caseback against IWC before you buy.