This adapter transforms the wired headset bluetooth headset. With the standard 4.1, it allows to have very little quality loss. It has its own equalizer (it is changed by flight + and - buttons simultaneously). To change the language, just to pressing the power button at the same time that the volume button less. After 2 months of use, the battery will not hold a charge after the power off. Therefore, I contacted Bluedio sent me to Amazon. Amazon makes me return the product and refund me. Bluedio, that's it for me this is the material that appears well made but did not.