Short answer

There is no reference 16402 in Audemars Piguet's Royal Oak catalog. That number shows up in marketplace shorthand and in replica listings, and when you trace it back it almost always points to a 41mm Royal Oak (15400 or 15500) or a 39mm Jumbo (15202 or 16202). So if you are searching for a fake Audemars Piguet Royal Oak 16402, you are really shopping for a replica of one of those four references. The questions that decide whether the watch is worth the money are the same for all of them.

Start with the reference, not the photos

Sellers mix numbers up, sometimes on purpose. Before you compare a single photo, ask one question: what is the exact case size and which movement is inside? A 41mm case and a 39mm case wear nothing alike, and the bracelet taper is different. If the listing cannot answer that in one sentence, move on. I have seen the same watch photographed under three different reference numbers on three different sites.

How replica Royal Oaks are graded

The market sorts into rough tiers. Knowing which tier you are looking at explains the price gap better than any photo.

  • Budget tier. Often a Miyota or low-grade automatic, mineral or thin sapphire, printed dial texture. Case thickness lands near 11.5mm on a watch that should be under 10mm.
  • Mid tier. Japanese automatic with a decorated rotor, real sapphire, decent tapisserie pattern. Good daily wear, obvious to anyone who handles a genuine one.
  • High tier or super clone. Custom or clone movement, correct thickness, bevelled case edges, stamped clasp and caseback engraving. This is where most serious buyers settle.

Movement: the part that gives it away

Genuine Royal Oaks use in-house calibers, and the 2121, 3120 and 4302 all have a specific feel when you wind them and a specific rotor sound. Replicas rarely get this right. A decorated Miyota 9015 is common in 15400 replicas and it runs fine, but the winding is gritty and the rotor is louder than it should be. Custom clone movements are closer, and they cost more. Ask for a timing machine printout if you can. Anything running past about plus or minus 15 seconds a day out of the box is not tuned.

Case and bezel

This is where high tier replicas split from the rest. Genuine 41mm Royal Oaks sit at roughly 9.8mm thick, and most replicas come in thicker. Measure it, do not trust the spec sheet. On the bezel, check the eight screws: the slots should line up on a consistent axis, and the heads should sit flush rather than proud. Look at the case flanks too. Real ones have a brushed surface with a polished bevel that runs the full length. A lot of replicas skip the bevel or polish it too soft.

Dial, hands and date

The Grande Tapisserie pattern is the tell most people miss. On the original, each square is a small pyramid with crisp edges and a matte top. On cheaper replicas the pattern looks flat, or the squares are too large or too small for the dial diameter. Check the date window font and position. Then check the hands: the polished bevel down the center of each hand should catch light as a distinct line. If the hands look like one flat piece of metal, that is a budget build.

Bracelet and clasp

Ask for a photo of the clasp with the logo. Stamping depth and letter spacing are usually the weakest point on a replica, even a good one. On the bracelet, look at the link edges and the end link fit against the case. Gaps you can see with the naked eye are a sign the tolerances were not held.

Before you pay, get these five things

  1. A short video of the watch running with the crown pulled out and pushed back in.
  2. A measured thickness in millimeters and a total weight in grams.
  3. The movement name, stated plainly, without the word "Swiss" doing the work.
  4. A clear photo of the caseback engraving and the clasp stamp.
  5. A written return window and a payment method that gives you a dispute path.

Red flags

"Swiss made" on a replica usually means a Swiss movement dropped into a case made elsewhere, which is not the same thing as Swiss manufacturing. Watch for sellers who refuse close-up photos, who only show one angle, or who price a mid tier watch like a top tier build. And keep the legal side in view: selling a counterfeit as genuine is fraud, and counterfeit watches are subject to seizure at the border. Buy what you want to wear, not something you plan to pass off as the real thing.