Answer
IW544716 is an IWC reference number. "IW" plus six digits is the IWC format. The first four digits, 5447, name the Portuguese Tourbillon Mystère. The last two, 16, name the case and dial version. A fake IW544716 is a counterfeit of that watch. Genuine examples sell for tens of thousands of US dollars and up. Counterfeits sell for a few hundred to about two thousand dollars. An IWC in-house tourbillon caliber is not sold on the open market.
Why the reference matters
A reference number ties a watch to a caliber, a case metal, and a dial. The 5447 base covers several variants. Two watches can share the base reference and differ in metal, dial color, and production year. A seller who gives "IW544716" without photos of the caseback leaves the variant unconfirmed. Ask for the full engraving and the serial number.
Six checks
1. The tourbillon cage
Look through the aperture in the dial. The cage turns one full rotation per 60 seconds. Time it with a stopwatch. A static cage, a printed disc, or a balance wheel under a shaped bridge fails this test. Low-cost tourbillon modules do rotate. Compare screw heads, bevels, and pivot finish against photos from IWC and from auctions.
2. Caseback engraving
IWC puts the reference, the serial number, the case material, and hallmarks on the caseback. Letter depth is even and spacing is constant. Counterfeits show shallow stamps, wide spacing, or one serial number that appears in many listings. Search the serial number before payment.
3. Case metal and weight
An 18k gold case weighs more than a gold-plated steel case of the same size. Plated cases show wear at the lugs and the caseback rim after months of use. A jeweler can run an acid test or X-ray fluorescence to read the alloy.
4. Movement
Open the caseback with a watchmaker present. IWC finishes in-house calibers with striped bridges, polished screws, and the IWC name on a bridge or rotor. Counterfeit movements show laser etching, uneven stripe depth, and generic shock springs. Record the jewel count and compare it to the IWC figure for the caliber.
5. Dial printing
Dial text on the genuine watch is thin. The IWC logo, the Schaffhausen line, and the Swiss Made line sit inside tight tolerances. Copies show thick strokes, ink bleed at the edges, and letter spacing that drifts.
6. Papers, box, and price
Genuine watches come with a warranty card, a numbered box, and a service history. A tourbillon without a service record raises cost questions. If the asking price is under about ten thousand US dollars, treat the watch as a counterfeit until a watchmaker proves otherwise.
What to do
- Request photos of the caseback and the movement.
- Request a 60-second video of the tourbillon cage.
- Check the serial number against IWC service records.
- Pay for an independent inspection before purchase.
Limits
IWC does not publish full production numbers for ref. IW5447. Variants change without notice. No guide confirms one watch. A watchmaker with the watch in hand can.