Before that, there was a prior series that folded up, and after about a year and a half of use, they were sent away for replacement components. In addition, we had two of these headphones, and even though we got them at the same time, they both stopped working at the same time. In general, when it comes to Sony products, you can sort of anticipate a higher build quality and plastic that isn't quite as cheap. It does not present well visually, and it is disintegrating much more rapidly than anticipated. Despite the fact that I blow out the dust particles from them, it is fascinating to see how rapidly they will come apart.