Quick answer
IW544746 is an IWC reference. The number follows IWC's format: "IW" plus a four-digit family code (5447) plus a two-digit variant code (46). The 5447 family is tied to the Portugieser Tourbillon Mystère, a hand-wound watch with a flying tourbillon at 12 o'clock. IWC's public catalog does not list a current model under that family, so the reference belongs to a discontinued line. Two-digit suffixes change with case metal and dial, so confirm the exact 544746 configuration with IWC before you treat any listing as genuine.
Most pages that rank for this number are replica listings. That is the first warning sign. A tourbillon IWC is a five-figure watch on the secondary market. Any offer far below that is not a bargain.
Case and finishing
Measure the case. Replica cases often run thicker than the original and the lugs sit wider. Look at the lug profile from the side: genuine Portugieser lugs taper with a polished bevel that runs the full length. Replica lugs are cut straight and the bevel stops short.
Check the crown. IWC crowns carry the probus scallop logo on the flat end. Replica crowns show a soft blob, a shallow stamp, or no mark.
Dial
- Text: "International Watch Co." and "Schaffhausen" must be sharp at 10x. Replica printing feathers at the edges.
- Tourbillon aperture: the cage sits at 12 o'clock. A real flying tourbillon rotates one full turn per minute and the balance oscillates inside it. Fake cages use a printed disc or a motor that spins at a constant speed with no balance motion.
- Hands: leaf-shaped, with a flat polished face and a sharp center ridge. Replica hands are thinner and reflect light in a dull band.
Movement
Open the caseback. A genuine Mystère runs a hand-wound caliber. There is no rotor. You see Geneva stripes, polished screws, and jeweled chatons. Replica movements are automatic units with the rotor removed, or a quartz module behind a decorated plate. Winding feel tells you more than photos: a real hand-wound IWC winds smooth with no grit and no backlash.
Caseback and paperwork
Engraving depth is the test. Genuine engraving is cut into the metal. Replica engraving is laser-etched and shallow. Compare the case number to the number on the papers and the warranty card. Replica sellers reuse one case number across many units, so search the number before you buy.
Before you buy
- Ask for a movement photo with the caseback open.
- Ask for the reference and case number.
- Request an archive extract from IWC for the serial.
- Have a watchmaker time the tourbillon cage. One turn per minute, no exceptions.
What I could not verify: the exact case metal, dial color, and production year tied to suffix 46. IWC does not publish that detail in its open catalog. Treat any seller who states it without a document as a risk.