Quick answer
The Audemars Piguet 26400RO is a 44 mm Royal Oak Offshore chronograph. The case is 18k rose gold. The bezel is black ceramic with eight hexagonal gold screws. The dial is black with a Mega Tapisserie pattern. Audemars Piguet built the reference from about 2010 to 2017, then replaced it with the 26420.
Replica versions of this reference exist in several tiers. The main differences from the genuine watch are case thickness, case weight, gold content, movement construction and caseback engraving. Those four points decide the price of any replica.
Genuine reference data
- Reference: 26400RO.OO.A002CA.01
- Case: 44 mm wide, 14.4 mm thick, 18k rose gold
- Bezel: black ceramic, eight gold screws
- Movement: calibre 3126/3840, automatic, 3 Hz, about 50 hours of power reserve
- Functions: hours, minutes, small seconds, date at 3, chronograph with 30-minute and 12-hour counters
- Water resistance: 100 m
- Crystal: sapphire, front and display back
- Strap: black rubber or hornback alligator, gold pin buckle
Replica tiers and makers
Names that appear in this market include JF, APSF and ZF. I cannot verify which workshop holds the closest copy. Grades split into three groups. Entry versions use quartz movements, a steel case with thin plating and a printed dial. Mid versions use an Asian 7750 chronograph movement. Top versions use a modified movement built to look like the 3126/3840, with a decorated rotor and engraved bridges.
The 7750 layout matches the genuine dial: subdials at 12, 6 and 9. That match is why mid-tier copies read correct at arm's length.
How replicas differ
- Thickness. The genuine case is 14.4 mm. A 7750-based case runs about 15.5 mm to 16.5 mm. That 1 mm to 2 mm shows under a shirt cuff.
- Weight. The genuine case is solid gold. Replica cases are steel with plating or gold wrap. The head weight differs by about 30 g to 50 g.
- Gold. Plating of 3 to 5 microns wears at the lugs, crown guards and clasp. Gold wrap lasts longer. Color still drifts toward copper or yellow next to 18k.
- Movement. Rotor engraving, bridge bevels, jewel count and balance regulation all differ. The genuine calibre has 59 jewels.
- Dial. Square size and depth on the Tapisserie grid, date font, print thickness and hand finish are the points to compare.
- Bezel screws. Slot depth, slot width and alignment vary.
- Caseback. Engraving depth, letter spacing and serial placement vary.
What to inspect in photos
- Ask for the case thickness measured with calipers.
- Ask for a photo of the movement through the caseback.
- Check subdial positions at 12, 6 and 9 against the date at 3.
- Check the crown guards and the ceramic bezel edge for machining marks.
- Run the chronograph and confirm the reset returns to zero.
Market context
Genuine 26400RO watches trade on the secondary market for tens of thousands of dollars, with price set by box, papers, service history and condition. Replica listings run from under USD 100 for quartz versions to several hundred dollars for the higher tiers. I cannot verify those figures.
Legal status
Replicas are unauthorized copies of a trademarked design. In the United States, trafficking in counterfeit goods is a federal offense under 18 U.S.C. 2320. Customs and Border Protection can seize shipments, and import or resale carries legal risk.