Top pick: a timed, in-hand inspection by an independent watchmaker before any money moves. The criteria that decide the outcome are the movement and its tourbillon behavior (where the reference has one), the dial and case finishing under magnification, the caseback engraving and serial layout, and whether the paperwork survives a check against IWC's own published reference data. Photos and listing text narrow the field. Only the watch settles it.
What a fake IW545175 usually means
IW545175 belongs to IWC's 5451 reference family, which collectors associate with the Portugieser Tourbillon Hand-Wound line. Confirm the exact case metal, dial and movement spec against IWC's catalog before you compare anything, because the same base reference can appear in several finishes. Once the spec is firm, the word fake covers four different situations: a complete replica built from scratch, a genuine watch with swapped dial, hands or movement parts, a lower reference dressed up with a 545175 caseback or papers, and a genuine watch paired with fabricated documentation. Each one fails a different test, which is why a single photo check is not enough.
- Works well: pinning the official spec first, because it turns every later comparison into an objective yes or no.
- Falls short: trusting a listing that simply uses the reference number as proof of anything.
Criterion 1: Movement and tourbillon behavior
If the watch has a tourbillon, time the cage. It should complete one rotation per minute. Use a phone stopwatch, pick a fixed point on the cage, and watch it over five minutes. A decorative open-heart cutout or a small seconds hand dressed up as a cage will not hold that rate. Where a replica does carry a real tourbillon, the movement is usually sourced from a third party, so bridge shapes, jewel count and finishing rarely match the original. Look at the engraving under a loupe: flat, machine-stamped lettering and unfinished surfaces beneath the balance are common tells. The calibre markings on the movement should agree with the reference and case numbers on the caseback and with the paperwork.
- Works well: the one-minute rotation test, which is almost impossible to fake with a decorative cutout.
- Falls short: it needs a watchmaker or a patient buyer with a loupe and good light.
Criterion 2: Dial, hands and case finishing
At macro distance, check applique placement, printing weight and the polish on the hands. Applied indices should sit level and evenly spaced; printed text should be crisp at the edges rather than soft. Look at the case flanks and lugs: sharp transitions, even brushing and consistent bevels are hard to reproduce cheaply. On tourbillon references the dial aperture is usually cut cleanly and finished at the edge, while replicas often leave a rough or slightly oval opening because the movement was not designed for that dial.
- Works well: catching franken watches, where one part came from a different reference or finish.
- Falls short: good replicas can match a dial closely enough that only a side-by-side comparison helps.
Criterion 3: Caseback, engraving and paperwork
Reference and case numbers are typically engraved on the caseback, and on display-back models they should line up with what the movement and papers say. Check the depth and finish of the engraving, the fonts, and whether the numbers are consistent across caseback, guarantee card and service history. Ask for the original invoice and any service records, then verify the seller's story: an owner of a low-volume tourbillon usually has a traceable purchase path. Gaps there matter more than a scuffed box.
- Works well: exposes fabricated paperwork and mismatched case numbers.
- Falls short: some sellers have convincing documents and a swapped caseback on a genuine watch.
Route A: buying a replica IW545175
If you want the look and accept the compromise, ask the seller for a movement photo, a video of the tourbillon running with a timer visible, and the exact dimensions. Replicas of a tourbillon reference sit at the top of the replica market, so the gap between a good one and a bad one is wide.
- Pros: far lower cost than genuine, and a well-built example can look convincing on the wrist.
- Cons: no manufacturer service, uncertain water resistance, weak resale, and counterfeit goods can be seized at import.
Route B: buying a pre-owned genuine example
A genuine 5451-family watch is a low-volume piece, so condition and completeness drive value more than the model name. Insist on a third-party inspection with the caseback opened and the movement timed.
- Pros: serviceable movement, documented history, real resale value.
- Cons: higher entry price, and genuine watches with swapped parts still exist on the secondary market.
Use-case recommendation
If your goal is a visual match for occasional wear and you accept the servicing and legal limits, Route A with a movement video and a timed tourbillon clip is the practical choice. If you want a watch you can service, insure and sell later, Route B with a watchmaker inspection is the only route that holds up. If you already own a suspect watch, stop at the timed tourbillon test and the caseback numbers, then take it to a watchmaker before you spend on anything else.
Quick in-hand checklist
- Time the tourbillon cage over five minutes: one rotation per minute.
- Compare the dial and case against IWC's published spec for the reference.
- Match caseback numbers to movement markings and paperwork.
- Check engraving depth and font consistency.
- Confirm the seller's purchase and service history.
- Have a watchmaker open the case before you pay.
Legal note
Counterfeit watches are illegal to import into the United States and can be seized by customs, and selling one as genuine is trademark infringement. Treat any replica as a novelty item, not an investment.