If you are searching for a "fake Audemars Piguet Royal Oak 15311," here is the short answer: 15311 is not a reference number Audemars Piguet has ever catalogued. The Royal Oak references in that size and generation family are the 15300 (39mm) and the 15400 (41mm). So the top pick in this guide is the 39mm Royal Oak 15300, the genuine watch most "15311" listings are actually imitating, and the criteria used throughout are reference accuracy, case diameter and thickness, dial texture, movement layout, and bracelet finishing. Measured against those five points, a listing advertised as a "15311" fails the first one before you ever open a photo.

Why the number 15311 is the first red flag

Reference numbers are the backbone of how Royal Oak collectors verify a watch. They drive parts lists, service records, and auction descriptions. A seller who names a model "15311" is working from a number that returns nothing in the manufacturer's own catalog. The usual causes are a typo for 15300, a mashup of 15300 and 15400, or a made-up number chosen to make a listing sound rare.

  • No factory specification exists to compare against, so dial color, hand set, and case thickness cannot be verified.
  • Searches for the number lead back to other listings rather than to brand documentation.
  • Sellers who invent references often recycle the same photos across several ads.
  • Buyers tend to notice the mismatch after payment, when returns are hardest.

The Royal Oak 15300 (39mm): the closest genuine reference

The 15300 arrived in the mid 2000s with a 39mm case, the stamped tapisserie dial, and an integrated bracelet. It is the watch that most 39mm "15311" ads are copying, which is why it works as your benchmark.

Pros

  • 39mm proportions sit between the older 36mm Royal Oaks and the later 41mm models, which suits smaller wrists.
  • Calibre 3120 with a display back makes inspection possible without opening the case.
  • Documented reference number, so condition, service history, and value can be checked against real records.

Cons

  • Out of production, so genuine examples trade on the secondary market and need provenance review.
  • Service costs on a genuine piece run well above what any replica listing suggests.

Best for: anyone benchmarking a 39mm listing and checking case proportions against a real, documented watch.

The Royal Oak 15400 (41mm): the other reference behind most "15311" claims

The 15400 is the larger sibling, launched in 2012 with a 41mm case and the same calibre 3120 family. Listings that blend 39mm text with 41mm photos usually trace back to a confusion between these two references.

Pros

  • Modern sizing that reads larger on the wrist and matches current Royal Oak proportions.
  • Wide documentation, so dial variations and bracelet versions are easy to confirm.

Cons

  • Wears noticeably bigger; a 39mm ad illustrated with 41mm photos is a mismatch worth flagging.
  • Higher secondary market pricing than the 15300 for comparable condition.

Best for: buyers who want the current large-case look and need a reference to compare photos against.

Criteria that separate a genuine Royal Oak from a fake

  1. Case diameter and thickness, measured rather than estimated. Royal Oaks are slim for their size, and thick cases are a common tell.
  2. Tapisserie dial texture: consistent depth and sharp edges across the whole pattern, not a soft print.
  3. Movement: calibre 3120 should show a free-sprung balance and a properly finished oscillating weight through the caseback, not a generic rotor with a name applied.
  4. Bracelet and clasp: links that taper correctly, screws that sit flush, and a clasp that closes with even tension.
  5. Date window and printing: correct font, correct magnification, and alignment with the dial ring.
  6. Caseback engraving: even depth, correct spacing, and a reference and serial that match each other.

Legal and practical reality in the United States

Counterfeit watches that carry a protected trademark are illegal to import and to sell in the United States. Shipments can be seized at the border, and trademark counterfeiting carries civil and criminal exposure. Beyond the legal side, the practical cons are consistent: no manufacturer warranty, many independent watchmakers decline to service counterfeit movements, water resistance claims are unverified, and resale value is close to zero.

Recommendation

If the number 15311 is what brought you here, treat it as a warning sign rather than a model name. Use the 15300 as your benchmark for 39mm listings and the 15400 for 41mm listings, and walk away from any ad that cannot name a real reference. If you want the Royal Oak look, either save for a genuine piece with documentation or choose a watch that does not imitate another company's trademark. If you buy from the replica market anyway, price it as a disposable item, expect no service and no resale, and understand that border seizure is a real risk.