Audemars Piguet Celebrates Half A Century With It’s First Royal Oak Selfwinding Flying Tourbillon Openworked

Back in 1986, Audemars Piguet introduced the world’s first selfwinding tourbillon wristwatch. Calibre 2870 was housed in an ultra-thin case measuring a mere 5.3 mm in thickness, fitted with a winding system on the caseback side. Its tourbillon cage is