Short answer

The Audemars Piguet Royal Oak 67651 is a 33 mm quartz watch. Steel versions carry the code 67651ST, and a ZZ block in the reference marks a diamond-set bezel. Fakes sold under that number show up at 33 mm to 35 mm, run a Miyota or Chinese quartz movement, use glass or synthetic stones, and carry shallow caseback engraving.

Reference facts for the 67651

  • Model: Royal Oak, quartz, 33 mm.
  • Movement: Audemars Piguet Calibre 2713, Swiss quartz. Service means a battery change and a gasket check.
  • Case: 33 mm across, steel on 67651ST examples. Sapphire crystal. Eight hex screws pass through the bezel and seat in the caseback.
  • Bracelet: integrated, tapered links, AP folding clasp with a stamped logo.
  • Water resistance: listed at 50 m on the 33 mm quartz Royal Oak references.
  • Stones: the ZZ bezel uses brilliant-cut diamonds. AP states the carat weight per reference.

Where fakes differ

  • Movement: some copies fit an automatic movement. The rotor adds thickness and a caseback bulge the quartz 67651 does not have.
  • Dial: the genuine dial grid is cut into the metal. Copies mold the pattern, so the squares look flat and the edges round over.
  • Stones: cubic zirconia shows more fire and no sharp table. A gem tester separates the two in seconds.
  • Engraving: laser marks on a genuine caseback have depth. Fake stamps are faint and the serial font is wide.
  • Finishing: genuine bevels are polished by hand. Copies leave machine marks on the bezel flanks and the clasp.

Checks to run before you buy

  1. Ask for a photo of the caseback. Read the reference and serial numbers.
  2. Send the serial to Audemars Piguet. The brand keeps a register and answers owner requests.
  3. Open the back with a watchmaker. Calibre 2713 carries the AP mark and the calibre number.
  4. Test the bezel stones. Diamond or cubic zirconia, no middle ground.
  5. Weigh the watch and compare it to the maker's listed figure. Copies run light.

Prices and law

Secondhand listings for a genuine 67651 sit above $10,000 and climb with gold cases and stone weight. Copies sell for $100 to $500. In the United States, trafficking in counterfeit goods is a federal offense under 18 U.S.C. 2320, and Customs can seize counterfeit watches under 19 U.S.C. 1526. A fake serial returns no record from the brand, so a buyer holds a watch with no service path and no resale value.