The fastest way to spot a fake Audemars Piguet Royal Oak Extra Thin is to measure its thickness. The genuine watch is 6.8 mm thick. Most fakes are 1 mm or more thicker because they use a standard movement. If the watch feels thick or sits high on the wrist, it is likely a fake.

Check the Case Thickness

  1. Use a digital caliper to measure the case from the caseback to the top of the crystal.
  2. Compare the measurement to the official 6.8 mm specification.
  3. Reject any watch that measures more than 7.0 mm.

Inspect the Movement

The genuine Royal Oak Extra Thin uses the caliber 2121. This movement is based on a Jaeger-LeCoultre design. It has a free-sprung balance and specific finishing.

  1. Look through the sapphire caseback with a loupe.
  2. Check for the correct bridge shape and jewel count (36 jewels).
  3. Look for the engraved Audemars Piguet logo on the rotor.
  4. Reject any movement that looks like a standard ETA or Miyota.

Examine the Dial and Hands

The dial on a genuine Extra Thin has a distinct tapisserie pattern. The squares are crisp and uniform. The hands are white gold and have a precise finish.

  1. Compare the tapisserie grid to a reference photo. Fakes often have a softer or misaligned pattern.
  2. Check the date window. It should be centered and have a smooth bevel.
  3. Inspect the hands under a loupe. Genuine hands have sharp, polished bevels.

Verify the Caseback and Engravings

Engravings on the caseback are a common weak point for fakes. The genuine watch has deep, crisp laser engraving.

  1. Look at the serial number and reference number. The spacing should be consistent and the edges sharp.
  2. Check the Audemars Piguet logo. The letters should be clean and proportional.
  3. Compare the font to official examples. Fakes often use a different font.

Test the Weight and Feel

The genuine watch is made of steel or gold and has a specific weight. A fake often feels lighter or heavier because of different materials.

  • Weigh the watch on a gram scale. A steel Extra Thin weighs about 75 grams with a bracelet.
  • Feel the bracelet links. They should move without binding and have no sharp edges.
  • Check the clasp. The double-fold clasp should snap shut with a solid click.