The Audemars Piguet Royal Oak Concept, shown in 2002, is a futuristic reinterpretation of the Royal Oak with a skeletonised dial, an openworked case and a tourbillon. The production model that followed uses titanium, with a hand-wound tourbillon movement and a GMT display. The details of size and movement differ by version, and I could not confirm the 2002 prototype’s specification from a single source.

It was AP’s concept watch for the 30th anniversary of the Royal Oak, which took the octagonal bezel and screws into a case with a bold, almost vehicle-like look. The Concept line later added carbon, ceramic and flying tourbillon versions, the best known being a green ceramic flying tourbillon GMT.

Collectors see the Concept as the start of AP’s modern experimental watches, and it has often divided opinion because of its look. The Royal Oak Concept line is still in production in newer versions.