Short answer

A replica Audemars Piguet Royal Oak Offshore 26420 copies a 42 mm steel chronograph. The genuine watch runs calibre 4404 with a flyback chronograph and a 70-hour power reserve. Most replicas run a modified third-party chronograph movement. Case thickness and subdial spacing are the two points where copies differ from the original.

Genuine reference points

  • Reference 26420SO.OO.A002CA.01: steel case, 42 mm diameter, about 14 mm thick.
  • Calibre 4404: integrated chronograph, flyback function, 70 hours of power reserve.
  • Ceramic bezel, sapphire caseback, water resistance rated to 100 m.
  • Dial with Mega Tapisserie pattern, three subdials at 3, 6 and 9 o'clock.
  • Retail price is above 40,000 USD. Secondary market prices move with condition and box and papers.

Where replicas differ

Case thickness. Many copies measure 15 mm to 16 mm. The genuine case is about 14 mm. A thick case sits high on the wrist and shows under a cuff.

Subdial spacing. The 26420 uses an in-house chronograph layout. Copies built on a 7750 base push the subdials toward the center of the dial.

Movement finish. Genuine calibre 4404 has hand-finished bridges and a gold rotor. Copies use engraved plates that mimic the look.

Dial print. Text weight and date font are common faults. The date window sits at 3 o'clock and should align with the outer track.

Checks before you buy

  1. Ask for caliper photos of case thickness at the lugs.
  2. Compare the subdial centers to the 3, 6 and 9 positions on a genuine photo.
  3. Check the tachy scale print. It should sit inside the inner bezel edge.
  4. Ask for a photo of the caseback and the rotor engraving.
  5. Confirm the chronograph starts, stops and resets with a firm pusher feel.
  6. Ask about water resistance. Most replicas are not pressure tested, so keep them dry.

Movement notes

Replica 26420 watches ship with one of two movement types: a decorated 7750 clone, or a clone built to look like calibre 4404. The 7750 clone is easier to service. Parts for clone 4404 movements are hard to source, and many watchmakers decline the work.

Legal note for US buyers

Counterfeit watches are illegal to import into the United States. US Customs can seize the shipment. Trafficking in counterfeit goods falls under 18 U.S.C. § 2320. A replica has no manufacturer warranty and no service support from Audemars Piguet.