Short answer: a fake IW545168 is a replica of IWC's hand-wound Portugieser from the 5451 reference family, a large, thin dress watch with small seconds at 9 o'clock. The good ones nail the case proportions and the dial layout. The bad ones get the thickness wrong, print the numerals too heavy, and hide a cheap movement behind a solid back. Here is what to look at.
What the reference actually is
The 5451 line covers IWC's hand-wound Portugieser models: round case, slim bezel, leaf-shaped hands, a small seconds subdial, and a dial built around space rather than complications. The tail of the reference number (the 168 part) points to one specific case metal and dial combination, so the color of the dial and the case finish matter if you want the replica to match the real thing. Because the design traces back to a pocket-watch movement dropped into a wristwatch case, the whole look depends on a thin profile and a clean face. A replica that bulks up the case loses the point of the watch.
Case and crystal: where most copies slip
- Diameter sits in the low 40s to about 44mm depending on the variant. Measure it if you can, since sellers often round up.
- Thickness is the giveaway. Original cases are slender. Copies using a thicker movement run 1 to 3mm deeper, and that extra depth changes how the watch sits on the wrist.
- Crystal should be domed sapphire with anti-reflective coating on both sides. Cheaper builds use mineral glass or a flat sapphire with no inside coating, which shows glare and a washed-out dial.
- Lugs are thin and curved. Rough copies cut them thick and blunt, and the spring bar holes sit too far from the edge.
Dial details that separate tiers
Applied numerals on the original sit slightly raised and catch light along their edges. On low-tier replicas the numerals are printed flat or glued on crooked. Look at the small seconds track: it should be a fine, evenly spaced ring. Copies often print it thick, and the hand inside it lines up poorly at 12. The name and city text under 12 should be crisply printed with consistent stroke width. One quick check: the hand-wound Portugieser has no date. If a listing shows a date window, it is not copying this reference.
Movements you will see inside
The genuine watch runs an in-house hand-wound calibre. No replica maker clones it. What you get instead is usually an Asian hand-wound movement based on the 6497 or 6498 layout, or a decorated automatic tucked behind a solid caseback. Since the back is closed, you judge the movement by feel: winding should be smooth with light resistance, and the seconds hand should sweep evenly at 21,600 beats per hour. A choppy or jumpy seconds hand means a lower beat rate. Anyone advertising a "1:1 clone movement" for this reference is describing a decorated 6497.
Price tiers and what they buy
- Under $150: mineral glass, printed dial, thick case, basic strap.
- $200 to $400: sapphire crystal, better dial printing, 6497-based hand-wind, decent case finishing.
- $450 and up: closest match on thickness and dial, double AR coating, sharper lug work, better hardware and strap.
Pre-purchase checklist
- Ask for the actual case diameter and thickness in millimeters.
- Confirm crystal material and whether the coating is on one side or both.
- Request a close photo of the subdial and numeral edges.
- Ask which movement is inside and its beat rate.
- Check lug width matches the strap you plan to use.
- Confirm water resistance claims are realistic, and do not swim with a replica.
Match the reference details first, then the price. A replica that gets the thin case and clean dial right will look closer on the wrist than one with a fancier name on the rotor.