Short answer
Reference 16402 does not appear in the Royal Oak numbering that Audemars Piguet, auction houses, and collector reference guides use. Search for it and you are almost certainly looking at a Royal Oak Jumbo, reference 16202, or its long-running predecessor, the 15202. Both share the same recipe: a thin case, an octagonal bezel with eight screws, an integrated bracelet, and a textured tapisserie dial. That detail matters if you are buying, because the reference number is one of the first things a counterfeit gets wrong.
Why fakes cluster around this model
The Royal Oak gets copied more than almost anything else at its price. The reasons are practical. The case is thin and the back is sapphire, so a maker cannot hide a cheap engine behind solid steel. The dial has a raised grid that is hard to stamp cleanly. The bracelet has hundreds of small surfaces that have to line up. Resale values near or above retail pull counterfeits toward the model, and social media moves them fast. I look at the same sequence every time: the case shape gets close, the dial gives it away.
Tells on the dial
- Tapisserie grid. On a real Royal Oak the squares sit on a precise grid and the raised lines stay crisp and even. On fakes the grid drifts, square sizes vary, and the pattern looks smeared near the edges.
- Print and logo. Look at the letterforms and the thickness of the line. Fake print often looks slightly bolder or lighter, and the AP monogram can sit a hair off center.
- Date window. Check the position against the dial center, the shape of the aperture, and the font of the numerals. Mismatched date fonts are common.
- Hands and markers. Genuine hands have polished bevels that catch light along the full length. Fakes look flat or have rough edges under a loupe.
Case, bezel screws, and bracelet
- Bezel screws. There are eight hexagonal screws, and their slots should line up in a consistent pattern. On many fakes the slots are decorative and sit at random angles.
- Chamfers and brushing. The case edges should have a bright polished bevel against a brushed flat. Fakes usually blur this transition.
- Thickness. A Jumbo is roughly 8mm thick. Plenty of counterfeits run thicker because the movement will not fit.
- Bracelet. Check the taper, the sharpness of each link edge, and how the clasp engraving is cut. Stamped, shallow text is a warning sign.
The movement is where most fakes fall apart
Genuine Royal Oaks in this family run the caliber 2121 or the newer 7121, both ultra-thin automatics with hand-finished bridges and gold rotors on many versions. Ask for a clear photo of the movement and a timegrapher video. In person, the giveaway is depth. Real finishing has bevels that reflect light along their whole length, and the engraving on the rotor is cut, not printed. Replica movements can photograph well and still feel wrong when the crown is wound.
Papers, boxes, and serials
Match three things: the case number engraved between the lugs, the number on the movement, and the number on the paperwork. Fakes frequently repeat the same number across a batch, which is easy to catch if you compare photos from two sellers. Boxes and cards are copied well enough that they should never be your proof.
What a counterfeit actually costs you
Audemars Piguet will not service or authenticate a counterfeit. No independent watchmaker will warranty one either, and parts do not exist. Resale is close to zero. On the legal side, selling a watch carrying a fake AP logo is trademark counterfeiting in the US and most of Europe, and imported counterfeit goods get seized by Customs and Border Protection. That risk sits with the buyer at the border, not just the seller.
A checklist before you pay
- Confirm the reference against AP's own catalog, not the seller's description.
- Request macro photos of the dial, the bezel screws, the clasp, and the caseback.
- Ask for a timegrapher reading and a movement photo with the back off.
- Compare the case number with the papers and the movement number.
- Take it to a watchmaker who knows the brand, or send it to AP for a service estimate.
- If the price is a small fraction of market, it is not a deal. It is a fake.
If you want the look on a budget, a watch from a brand that designs its own case is legal, serviceable, and keeps its value. A counterfeit Royal Oak keeps none of those things.