The Audemars Piguet 8638ST Tropical Royal Oak is a rare and unique timepiece designed for female clients, featuring a small self-winding caliber and a tropical dial that has developed an even brown patina over time. Its production run was limited to approximately 3,889 timepieces between 1976 and 1990. This particular watch may appeal to those looking for a smaller Royal Oak.

• Condition: Excellent
• Diameter: 29mm
• Case material: Stainless Steel