Well, first I love the battery upgrade, probably was the last thing to make ear (2) perfect. But for an engineering standpoint, the flexible PCB is quite interesting, that size contained in the housing and how it should folds, must be hard to assembly I presume. Of course the exterior design is just delicious and how they are displayed in the case, it really shows where Nothing shines, their design philosophy. I’ve just bought an earbuds, but when I saw the presentation I immediately wanted to try these new ones, hope I get the hands on it.