Quick answer
The keyword joins two IWC references that are not the same watch. IW3270 is the Pilot's Watch Mark XVIII, sold from 2016. "Mark 20" is Mark XX, reference IW3282, sold from 2022. Many replica listings put both numbers on one page. Read the caseback text in the photos before you compare anything.
Original specifications
Both references use a 40 mm steel case, a 20 mm lug width, and a black dial with white numerals.
- Mark XVIII, IW327001: caliber 35111, 42-hour power reserve, 11 mm case height, water resistance 6 bar, soft-iron inner case for magnetic shielding.
- Mark XX, IW328201: caliber 32111, 120-hour power reserve, 10.8 mm case height, water resistance 10 bar, EasX-CHANGE strap system, date window at 3 o'clock.
The Mark XX dial is flatter. The bezel is thinner. The date font is narrower.
What replica builds change
Mark XVIII and Mark XX copies come from factories such as ZF, MKS, V7F, and TWF. Stock and batch numbers change month to month, so no factory list holds for long. A common build uses an Asian 2892 base or a Miyota 9015, a sapphire crystal with coating on one side, and a printed dial.
Known gaps against the original:
- Case height. Copies run 0.5 mm to 1.5 mm thicker on most batches.
- Date window. Position shifts by 0.2 mm to 0.5 mm. Font weight is heavier.
- Lume. Copies read off-white. The original reads pale green.
- Crown and caseback engraving. Shallower cuts, wider logo strokes.
- Water resistance. Not tested at the factory. Do not swim with a copy.
- Movement finish. Rotor text is laser etched, not milled.
Checks before you buy a copy
Ask for a photo of the caseback with the reference number visible. Ask for the measured case height with calipers, not the listing figure. Ask which movement base sits inside. Sellers who answer these three questions in writing give you something to compare against the delivered item.
Legal status in the United States
Counterfeit watches are illegal to sell and to import. 18 U.S.C. § 2320 covers trafficking in counterfeit goods. CBP can seize shipments at the border, including single-item parcels. IWC does not service replicas. No factory warranty applies.