Short answer
A 'fake Portofino Small Seconds 39' is a replica of the IWC Portofino with a small seconds subdial at 6 o'clock. IWC does not list a Portofino at 39 mm. The catalog has the Portofino Automatic 37 (ref. IW4581) with small seconds, and the Portofino Automatic 40 (ref. IW3565) with central seconds. Sellers attach '39' to listings as a label. Measure the case with calipers before you pay.
What the genuine reference does
Ref. IW4581 uses a 37 mm steel case, a small seconds subdial at 6, a date window at 3, a sapphire crystal, and 50 m water resistance. The movement is calibre 35111, an automatic that runs at 28,800 vph. IWC fits an alligator strap. Ref. IW3565 moves the seconds to the center and measures 40 mm.
What replica listings claim
- Case size: one watch gets listed as 39 mm, 40 mm, and 41 mm across shops.
- Movement: 'Swiss ETA' labels sit on watches with Asian clones such as the A2892 or A35111.
- Strap: listings state alligator. Most units ship calf leather with a stamped grain.
- Water resistance: 3 ATM is a common claim. Factories do not pressure-test each unit.
- Weight: sellers publish weight less often than photos. Ask for a scale photo.
Checks before you buy
- Ask for a caliper photo across the case at 3 and 9 o'clock.
- Confirm the subdial sits on the 6 o'clock axis, not offset toward 5.
- Confirm date font and window shape. The genuine aperture has a bevel.
- Count beats. 28,800 vph reads as 8 ticks per second on slow-motion video.
- Ask for a caseback photo. Engraving depth on replicas is shallow.
- Check the crown logo and stem length.
Price bands
Entry replicas run $250 to $400. Mid tier runs $450 to $700. Listings above $700 claim Swiss parts. No replica carries IWC service or a factory warranty.
What no replica matches
Movement finishing under the display back, engraving sharpness, and strap leather. Water resistance is unverified on most units. Add the cost of a pressure test and a strap change to the purchase price.