SIGNED AUDEMARS PIGUET, TOURBILLON AUTOMATIQUE MODEL, REF. 25643BA, NO. 288, CIRCA 1990

Introduced in 1986, the Audemars Piguet automatic tourbillon was not only the first series produced commercial wristwatch combining these two complications but is still arguably the thinnest automatic tourbillon wristwatch ever made with an overall thickness of only 4.8 mm. Perhaps the two most outstanding features that made this possible are a tourbillon cage made of titanium, dramatically reducing the weight and therefore the power required for the escapement, and the incredible innovative solution of mounting some of the jewels for pivots in the case back of the watch. Given the watch’s historical importance and the fact that it remains today unbeaten for thinness, this model will always remain a ground-breaking milestone in the chronicles of high horology.