In 2019, Audemars Piguet introduced the world’s thinnest perpetual calendar, with a 2.89mm movement and a 6.30mm case. The watch, the Audemars Piguet Royal Oak Selfwinding Perpetual Calendar Ultra-Thin (or Royal Oak QP Ultra-Thin to make it simple) in a titanium case with platinum alloy parts, was based on the RD#2 concept revealed a year […]