Royal Oak 25654

The 25554 re-engineered for water resistanceWater resistanceA watch’s ability to resist water entering its case under specified conditions, often stated as a pressure or equivalent depth. Seals can deteriorate and the crown can be damaged, so an original rating does not establish a vintage watch’s present resistance.: a large metal casing ring combined with a big rubber gasket, raising thickness to 8.3 mm. Otherwise looks the same, and many 25554s were converted into it. Usually a plain (non-Tapisserie) dial; no leap-year display. Collectors split dials into Mark 1 (small “Audemars Piguet” lettering) and Mark 2 (larger, conventionally capitalised name).