Audemars Piguet Royal Oak Yellow Gold 8638BA

Brand : Audemars Piguet
Model : Royal Oak ll
Reference : 8638BA (the first lady Royal Oak ever produced!)
Caliber : Automatic
Diameter : 29mm
Limited edition of 824 pieces ever made
Year : 1978
Accessories : Original box and extract of the archives 
 
Launched in 1976, the Royal Oak II was the very first variant of the original Royal Oak Jumbo ref. 5402 (39 mm), designed for a female audience.
Despite being reduced to a 29 mm case, and powered by an ultra-thin automatic caliber, it became an instant success.