Perpetual Calendar Chronograph in Yellow Gold 'Fourth Series' EX080123 later known as the Tank

later known as the Tank Asymétrique

Our favourite of the final Audemars Piguet Royal Oak 15202's

This example from 2010

including the hands and

This example

Perpetual Calendar Chronograph in Yellow Gold 'Fourth Series' EX080123 later known as the TankIntroduced by Patek Philippe in 1986, the Reference 3970 holds a legendary position as the brand's third serially produced perpetual calendar chronograph, following the iconic 1518 and 2499. As a transitional masterpiece, the 3970 perfectly bridged the gap between vintage charm and modern reliability, making it a cornerstone for any serious watch collection. This 18K yellow gold (3970EJ) example dates to 2001 and belongs to the coveted Fourth Series.