Introducing a leap year indicator to Audemars Piguet’s Royal Oak Perpetual Calendar, the reference 25820 was launched in 1996 and remained in production until 2013, totaling just 628 steel examples. This timepiece features the renowned blue dial, often referred to as the “Yves Klein” due to its striking hue.

The fascination with the sky and its colors inspired French painter Yves Klein to create a vibrant shade of sapphire blue, which he believed encapsulated the essence of space. This color, known as "International Klein Blue (IKB)", became a central theme in Klein's artwork. When Audemars Piguet introduced a similar vibrant blue in their watches, collectors quickly adopted the nickname "Yves Klein". The present timepiece showcases the iconic petite tapisserie dial, enhanced by a lacquered texture at the calendar registers, creating a captivating contrast.

The case is well-preserved in excellent condition, with very crisp edges on both the case and bracelet. At 39mm, it mirrors the dimensions of the original Jumbo ref. 5402, marking the final 39mm iteration before Audemars Piguet transitioned to the new cal. 5134 in 2015, which debuted the larger 41mm ref. 26574. This present watch is surely a future classic, making it an ideal choice for the distinguished Audemars Piguet collector seeking an attractive and collectible timepiece.