Short answer
IW545128 is an IWC reference. The six digits split into a base reference (5451) and a variant number (28). Market listings place 5451 under the Portugieser family. IWC's own archive is the source that confirms which dial, case metal and strap variant 28 covers. Replica sellers use the number as a label, so the copy you receive can differ from the photo set.
Three points decide quality: case diameter and thickness, dial print and subdial position, and the movement inside. Ask for a measured case and a photo of the case back before payment.
What the number means
IWC writes references as IW plus six digits. The first four digits name the base reference. The last two name the variant, which covers dial color, hands, strap and case material. A buyer who searches the full string sees fewer results than a buyer who searches 5451. Both searches lead to the same family.
Checks on a replica
- Case diameter. Ask the seller to measure with calipers and send the photo. A stated 42 mm copy that measures 44 mm wears large on a 17 cm wrist.
- Thickness. Hand-wound Portugieser cases sit thin. A thick copy points to an automatic movement inside.
- Case back. A hand-wound watch has no rotor. A rotor visible through a display back means the movement differs from the original.
- Dial print. Look at the IWC wordmark, the SCHAFFHAUSEN line and the numeral edges at 10x zoom. Blurred edges show pad printing rather than applied markers.
- Subdial. The small seconds track sits at 6 o'clock on Portugieser models. Check that the subdial sits on the vertical center line.
- Crown. The crown should sit flush with the case band and carry the same logo as the genuine part.
- Strap and buckle. Alligator-print leather and a signed buckle are standard in the top grade.
Movement
Copies of hand-wound IWC models carry one of three movements: a decorated Chinese hand-wound, a Seagull ST17 base, or a Swiss ETA or Sellita base. The Swiss option costs more and holds time better. Power reserve on the Chinese units runs near 40 hours. A genuine hand-wound Portugieser uses an in-house IWC calibre, so no copy matches the movement architecture.
Price and delivery
Listed prices for IWC copies run from about $120 to $400. The number tracks the movement and the finish, not the reference string. Sellers in this niche ship free in the US and quote 7 to 21 days for delivery. Customs checks can add time. Pay with a method that allows a chargeback if the watch does not match the photos.
What is not known
Public sources do not document variant 28 with dial photos and full specs. Treat any listing that shows exact strap and dial data for IW545128 as a claim from the seller, not from IWC.