This J-serial Audemars Piguet Royal Oak Double Balance Wheel Openworked Ref:15407ST.OO.1220ST.01 is new unworn dated in March 2018. The Royal Oak Double Balance wheel Openworked tackles these stabilising issues by fixing a second balance wheel and balance-spring assembly on the same axis. The new patented geometry involves a very complex manufacturing procedure, but the payoff is huge: greatly improved precision and stability.
