Audemars Piguet Royal Oak Double Balance Wheel Openworked is the first watch use new double-balance wheel escapement. It is displayed at SIHH 2016.
Now AP has produced a few very high-end watches in the past that used two balance springs, but not two balance wheels. They include the Millenary Quadriennium and Millenary Minute Repeater with AP Escapement. The thinking here is that having two balance wheels creates an oscillator with more mass, ensuring great stability – why, for example, you see huge oscillators in marine chronometers. In previous watches, the two balance springs would counteract the effects of gravity on the balance itself. Basically whenever the balance spring contracts, it tends to push the sides of the balance staff against the sides of the cap jewels. That extra friction affects rate, and it does so to a different amount depending on the position of the watch. 
This new Royal Oak takes things one step further and in fact features not only two balance springs, but two entire balance wheels. As you can see above, they are set against each other and should not only provide much greater mass but also work against each other to self-regulate. 
Now the other thing this watch offers is truly high end openworking and component finishing. The entire caliber is completely hand finished, and the interior angles that we see all over this movement are the product of nothing but the human hand. Like the most recent open worked RO’s, the 15407 features a stunning deep grey dial and gun-metal treatment that make the entire look far less ornate and old than traditional skeletonized watches. The golden balance bridge lets you know that there is a little something special going on there, too.
The Audemars Piguet Royal Openworked Double Balance Wheel is sized at 41 mm in diameter, features a 45-hour power reserve thanks to the thin 5.57 mm caliber 3132. It is available in both stainless steel and rose gold, both non-limited. More details, including pricing and availability to come!
