AUDEMARS PIGUET, ROYAL OAK PERPETUAL CALENDER REF. 25820ST 'BLUE COSMOS', A RARE AND ATTRACTIVE STEEL AUTOMATIC WRISTWATCH

Audemars Piguet introduced the perpetual calendar complication to the Royal Oak collection in 1983. The first QP reference (Ref. 25654 was) introduced in 1983 and was produced till 1998 and is believed to have been limited to just 422 pieces (in yellow gold).

The watch was powered by Cal. 2120/2800, an automatic movement based on Jaeger-LeCoultre’s legendary ultra-thin JLC Cal. 920. The Caliber 2120 was developed in 1967 with the support of Audemars Piguet. The movement was adopted by Patek Philippe and Vacheron Constantin too.

The reference 25820 was launched in 1998 and featured the 2120/2802 with leap-year indicator movement first seen on the limited edition 25810. The present reference has a rarely intense indigo blue that is referred to Blue Cosmos in the Extract from the Archive.