The "3399" on a fake Audemars Piguet perpetual calendar is a replica batch code used by sellers, not an Audemars Piguet reference number. Genuine AP perpetual calendars carry references such as 26574ST, 26674ST, and 25820, and they run in-house calibers like the 5134. A watch tagged 3399 is a counterfeit assembled from third-party cases and movements, and importing or reselling one in the United States can lead to seizure and legal penalties.
What does 3399 mean on a fake Audemars Piguet perpetual calendar?
The number appears in replica catalogs as a batch or version identifier, similar to the codes sellers attach to different dial colors and case finishes. It does not map to any Audemars Piguet reference, caliber, or catalog entry. Two listings sharing the same 3399 label can still differ in movement, dial, and thickness, because the code tracks a seller stock run rather than a fixed specification.
How can you tell a fake Audemars Piguet perpetual calendar from a real one?
Real AP perpetual calendars are judged on movement architecture, dial layout, and finishing depth. Replicas fail on at least one of those three points, even when the listing photos look convincing.
Subdial layout and calendar logic
A genuine 26574 shows day, date, month, moonphase, and week-of-year indicators that all advance correctly, including at month ends and leap years. Most clones use a modular calendar plate that jumps wrong, stalls on the 31st, or leaves the moonphase static. Check the week hand first, since replica makers rarely sync it.
Case thickness and finishing
The genuine Royal Oak Perpetual Calendar measures roughly 9.5 mm thick, with crisp hand-finished bevels on the octagonal bezel. Replicas add 1 to 3 mm because the cloned movement is thicker, and the bevels look soft or mirror-polished instead of brushed. A caliper reading is the fastest first test.
Dial printing and hands
Look at the text under the logo and the tapisserie pattern edges. Replica printing smears under magnification, and the grid is shallow. Genuine hands are diamond-polished with sharp facets that catch light in a single line.
Caseback, engraving, and movement
Genuine AP casebacks carry laser-etched reference numbers, a serial that matches AP service records, and a display back showing the 5134 with Geneva stripes and a skeletonized gold rotor. Clones show rough perlage, painted engraving, and reference or serial numbers that do not agree. A watchmaker can open the case in minutes and settle the question.
Which genuine references do counterfeiters copy most?
- 26574ST Royal Oak Perpetual Calendar in steel
- 26674ST Royal Oak Perpetual Calendar with ceramic details
- 25820 and 25654 vintage and neo-vintage perpetual calendars
- 26579CE black ceramic editions
What are the legal risks of buying a fake AP perpetual calendar?
In the US, 19 U.S.C. 1526 makes importing and trafficking counterfeit goods illegal, and Customs and Border Protection can seize shipments and destroy them. Penalties can include fines and, for commercial sellers, criminal charges. Reselling a 3399 watch as genuine is trademark counterfeiting and carries the highest exposure.
How much do these replicas cost?
High-end AP perpetual calendar clones sell between roughly $500 and $1,500 depending on movement and finishing level. That gap against a genuine piece, which runs well into six figures, is the clearest signal of what you are buying. Any listing that calls a 3399 watch authentic is either mistaken or fraudulent.
Bottom line
The 3399 tag is a seller label, not an Audemars Piguet identifier, and no replica reproduces the 5134 calendar logic or the Royal Oak finishing standard. Authenticate through AP service records, a trained watchmaker, and independent paperwork before money changes hands.