Short answer
A replica IW545105 is a copy of an IWC Portugieser hand-wound reference. The original runs an in-house IWC movement. No replica does. Buyers who use this search term compare case size, dial layout, crystal coating, strap, and the movement seen through the display back.
The reference number
IWC reference numbers start with IW and carry six digits. The 5451 block sits in the Portugieser line. The last three digits mark a case and dial variant. IWC publishes the original spec on its own site. Check there before you compare a replica against photos.
IWC stopped production of several 5451 references. Used originals trade above retail in some markets. That gap is why the number appears in replica listings. Sellers reuse the code for search traffic, and two listings with the same code do not always ship the same watch.
What to check on a replica
Case: diameter, thickness, lug width, finish. The Portugieser case has a thin bezel and long lugs. Copies often run 1 mm to 2 mm thicker because the movement has a different shape.
Dial: applied numerals and indices, printed minute track, sub-seconds hand position. On low-tier copies the numerals are glued on and sit above the dial surface. On better copies they sit flush.
Crystal: sapphire with an anti-reflective coating on both faces. Look for a blue or purple tint at an angle. Mineral glass shows scratches after months.
Movement: Asian clones of the ETA 6497 and 6498 hand-wound calibres are common in this case shape. Some sellers list a Swiss movement. Ask for a photo of the movement and the balance wheel. A 6497-based copy beats at 21,600 vph. An 8-day power reserve claim on a replica is not supported by the movement inside.
Strap and buckle: alligator or calf, 20 mm to 22 mm at the lugs. Folding clasps add weight. Check the tang or deployant for stamped logos against engraved ones.
Back: display caseback with engraved reference, case number, hallmarks. Engraving depth is shallow on low-tier copies.
Price bands
- Under $150: quartz or basic hand-wound, mineral glass, plated case.
- $250 to $500: 6497 or 6498 clone, sapphire, steel case, better dial print.
- $600 and up: decorated movement, closer case dimensions, alligator strap.
Price does not confirm origin. A $700 copy still holds an Asian movement.
Legal status in the US
Counterfeit watches are illegal to import and sell in the United States under 18 U.S.C. 2320. U.S. Customs and Border Protection seizes shipments. Buying for personal use carries lower risk than reselling, but the goods stay illegal.