Quick answer
A copy IW5105 is a third-party reproduction of IWC reference IW5105. Quality ranges from close to crude, and the seller's description is the least reliable part of the deal. Judge the watch against the official reference specs, measure the case yourself, and confirm the movement with photos and a timed power-reserve test.
What you need first
- The official spec sheet for IW5105 from IWC: case diameter, thickness, lug width, crystal, dial layout, caliber, power reserve.
- Digital calipers and a 10x loupe.
- Photos of the exact unit for sale, not catalog renders.
- A written return window before money changes hands.
How to check a copy IW5105
- Write the factory numbers for IW5105 on paper: diameter, thickness, lug width, caliber number, and power reserve in hours.
- Measure the replica case with calipers at the bezel and at the thickest point, then compare each figure to your list.
- Reject any unit that is off by more than about 0.5 mm in diameter or thickness, since the error usually means a substituted case or a different movement.
- Study the dial under the loupe and check letter weight, spacing, and alignment of the printing against a photo of the genuine dial.
- Inspect the hands for straight, even bevels and clean slots, because stamped or painted hands are the most common shortcut.
- Ask for a clear photo of the caseback interior and the caliber engraving, then match the caliber number to the official spec.
- Wind the watch fully, set it down, and time how long it runs before it stops; compare the result with the stated power reserve.
- Check the applied markers for glue halos and height, then press each one lightly to confirm it is seated.
- Work the strap, clasp, and crown through several cycles and note any grinding, wobble, or sharp edges on the caseback.
- Confirm the return terms in writing and pay with a method that allows a chargeback.
Common tells on IW5105 replicas
- Case thickness that runs high because a thicker movement sits inside.
- Dial text that looks heavier and softer at the edges than the original.
- Caseback engraving that is shallow, uneven, or missing fine detail.
- Movement stamping that does not match the caliber listed for IW5105.
- Power reserve that falls well short of the number in the official spec.
Legal and practical limits
Counterfeit watches shipped into the United States can be seized by customs, and the buyer carries the loss. Replicas also carry no manufacturer warranty, no service history, and no parts support from IWC. Resale value is close to zero. Treat the purchase as a disposable expense and inspect the unit before you pay, not after.