Short answer
IW544745 is an IWC reference number in the 5447 block. That block covers hand-wound Portugieser tourbillon watches. Public IWC spec sheets for 5447 references list a tourbillon at 6 o'clock, a hand-wound movement, a sapphire crystal, and a case near 43 mm. The exact "45" suffix is not in current public catalogs, so confirm the variant with the seller. A replica IW544745 is a copy of that watch, not an IWC product.
What the 5447 block contains
- Portugieser dial layout: thin leaf hands, applied numerals, a railway minute track.
- Tourbillon cage at 6 o'clock, open through the dial.
- Hand-wound movement, no rotor, no automatic winding.
- Case metal options across the block: steel, rose gold, white gold, platinum.
- Limited production numbers per metal.
IWC has changed the Portugieser line several times since the 1990s. Reference suffixes mark metal, dial color, and strap. A single suffix can mean a boutique-only run. Treat any suffix you cannot document as unconfirmed.
What replica makers copy
Good copies get the case profile, the dial print, and the lug shape close. The tourbillon opening is the hard part. A real cage holds the balance and escapement in a rotating carriage. Many replicas print a cage on the dial or mount a static bridge under a fake opening. Look at the cage under a loupe. It should rotate once per minute and carry the balance wheel.
Movement checks
- Turn the crown. A hand-wound movement gives resistance through the whole wind. A loose or gritty feel points to a cheap clone.
- Watch the seconds hand. A tourbillon watch often has no central seconds hand. A sweeping central seconds on a tourbillon dial is a warning sign.
- Listen. A real tourbillon ticks in a fast, even rhythm. Silence or a slow tick means a quartz or a plain mechanical movement.
- Check the power reserve. Hand-wound Portugieser movements run for days, not hours.
Case, dial, and finish
Measure the case with calipers. The 5447 group is listed near 43 mm. A copy at 40 mm or 45 mm is a different watch. Check the lug width and the strap fit. Check the dial print under magnification: the railway track should be crisp, and the numerals should sit level. Plated cases wear through at the lugs and the caseback edge, so look for brass color at the corners.
Before you pay
- Ask for photos of the movement with the caseback off.
- Ask for a video of the tourbillon cage running.
- Confirm the case metal and the measured diameter.
- Confirm the return policy in writing.
- Compare the asking price with other sellers for the same spec.
Care
A tourbillon has many small parts. Keep the watch away from magnets and drops. Wind it at the same time each day. Have it serviced when the rate drifts, not when it stops. Replica service options are limited, so ask who repairs it before you buy.