At 39mm, the steel case of this Royal Oak Openworked frames a transparent dial that forgoes numerals entirely, allowing an unobstructed view of the automatic Caliber 3129 beneath the sapphire crystal. A steel bezel completes the case, which carries a water resistance rating of 5 ATM.
Caliber 3129 is an automatic movement endowed with 38 jewels and a 60-hour power reserve — specifications that speak to the engineering depth housed within this iconic octagonal form. The steel bracelet and steel clasp extend the watch's monochromatic, architecturally consistent appearance from case to wrist.
Reference 15305ST.OO.1220ST.01 is presented complete with its original box and papers, making it a well-documented example of Audemars Piguet's openworked interpretation of the Royal Oak Selfwinding.
