The Audemars Piguet Code 11.59 Chronograph uses reference numbers in the 26393 family. Authentic watches run caliber 4401. That movement is an integrated chronograph with a column wheel, a vertical clutch, and a flyback function. Counterfeit versions copy the number format. They rarely copy the mechanics. The differences show up in the movement, the crystal, and the caseback.
What the reference code means
AP reference numbers follow a fixed pattern. The first block names the model. The second block gives the case metal. ST is steel. OR is pink gold. CR is white gold. TI is titanium. CE is ceramic. The suffix covers dial and strap.
- 26393ST: steel case, 41 mm.
- 26393OR: pink gold case.
- 26393CR: white gold case.
- 26393TI: titanium case.
Fakes print these codes on stickers, hang tags, and boxes. A code on a tag proves nothing. Compare the caseback engraving with the movement number.
Movement tells
Caliber 4401 offers a 70-hour power reserve. Fakes use a Valjoux 7750 base or a Chinese copy of that design. Four signs point to the fake:
- A 7750 base puts running seconds at 9 o'clock. That layout does not match the 4401 subdial set.
- Winding feels rough. The rotor rattles when the case turns.
- Chrono pushers feel soft. Genuine pushers give a firm click at start and stop.
- The rotor shows stamped logos. Genuine rotors carry beveled edges and Geneva stripes.
Ask for a photo of the movement through the display back. Fakes often ship with a solid steel back to hide it.
Crystal and case
The genuine crystal is double curved and gets anti-reflective coating on both faces. Photos of real watches show little glare. Fake crystals show a blue or purple cast and heavy reflections.
The Code 11.59 case has an octagonal middle case, a round bezel, and thin lugs. Bevels are polished. Lug tops are satin brushed with sharp edges. Fakes show rounded edges and uneven brushing. The bezel is often too thick.
Papers and warranty
AP issues a digital warranty record tied to the buyer. Paper cards dated after 2020 are a red flag. Fake sets ship with printed certificates that carry serials which do not match the case.
Checklist
- Compare the full reference against the AP catalog.
- Request a photo of the caseback and the movement.
- Check that case and movement serials match.
- Check the date aperture near 4:30.
- Weigh the watch. Gold feels heavier than plated steel, though weights vary by model.