The short answer
On a replica Audemars Piguet Code 11.59 listing, "45100" is not an Audemars Piguet reference and not a published AP caliber. Real Code 11.59 references read as 15210, 26393, 26395 and similar five-digit numbers. Treat 45100 as a seller SKU or a movement batch label, then judge the watch by details you can measure: case size, case architecture, dial print, movement finish, and clasp.
Before you start
- The seller spec sheet: claimed reference, case size, movement, and materials
- Macro photos of the dial, caseback, crown, and clasp
- A digital caliper and a 10x loupe
- A timegrapher or a phone timing app
Step-by-step check
Name the genuine model the listing copies. Ask the seller whether the replica targets the selfwinding Code 11.59 (ref. 15210 family) or the chronograph (ref. 26393 family). Write the answer down and hold the seller to it.
Test the 45100 code against other listings. Search the same code across sellers. If it appears on a chronograph and a three-hand watch, it is a stock number, not a movement designation.
Measure the case. The selfwinding Code 11.59 runs 41 mm across and about 10.9 mm thick. The chronograph runs about 12.6 mm thick. A replica that adds 0.4 mm or more sits high on the wrist and looks wrong under a cuff.
Study the case geometry. The line pairs a round bezel with an octagonal mid-case and hollowed lugs. Run a fingernail from the bezel down to the mid-case. A sharp ledge or a soft, rounded step points to weak finishing.
Read the dial with the loupe. Check the lacquer surface, the applied 3D logo, the minute track print, and the date window bevel. Print that sits above the lacquer or a flat logo with no depth is a fail.
Demand photos of the actual watch. Catalog renders hide flaws. Ask for a caseback and movement shot in daylight, with the rotor turned so the engraving shows.
Inspect the movement finish. Look for even perlage, straight Geneva stripes, clean jewel settings, and rotor engraving with crisp edges. Blurred text and glue around the jewels are warning signs.
Check caseback engraving and serials. Lettering should be level, deep, and aligned with the case axis. A pale, laser-etched look with a halo edge reads as a cheap mark.
Work the crown and pushers. Winding should feel smooth with no grit. On a chronograph, start, stop, and reset should snap and return to zero in one press.
Time the movement. Let the watch run for a day, then take readings in two positions. Note rate, amplitude, and beat error. A spread of more than 15 seconds per day between positions means a service or a return.
Finish at the clasp and strap. Check link screws, clasp engraving, strap stitching, and the folding action. A clasp that flexes or sticks will fail before the movement does.
Red flags to walk away from
- No macro photos of the movement or caseback
- The same 45100 code on watches of different sizes
- Case thickness stated as "same as original" with no number
- Pressure to pay outside a trackable method
- A price far under the rest of the market for the same spec
Legal note
Replica watches carry branded logos without authorization. Sale and import of counterfeits violate trademark law in the US, and customs can seize the parcel. Buy and wear with that risk in mind.