First released in 2002, reference 25977ST became immediately a grail for Audemars Piguet aficionados as it reunites - from a technical standpoint - the chronograph and the tourbillon, two among the most beloved and sought-after horological complications, and - from an aesthetic standpoint - fits them into an oversized 44mm Royal Oak case, undoubtedly the most iconic design of the band, and one of the most immediately recognisable in the entire field.