This Audemars Piguet Royal Oak reference 5402ST from 1977 is offered with a box and an extract from the Audemars Piguet archives. In 2022, a full service of the caliber 2121 was carried out at Audemars Piguet. The reference 5402 was produced until the end of the 1970s and can be divided into four different series: A, B, C and the D series. All series show small design differences, such as the positioning of the AP logo. While around 2000 examples of the A series were made, the B series is the rarest version of the reference with around 1000 examples. This model is one of the few B series produced in 1977. The condition of the watch can be considered very good, there are a few superficial streaks on the clasp and strap, but no deeper scratches/signs of wear.