Was looking on devices with wireless voice amplification, because I can only speak softly after an illness. I had already purchased a Nolan Bluetooth Wireless; it operates satisfactorily; his Aku-reserve enough for an 8-hour use. For the reception and amplification of my Bluetooth signal from the micro-I sat before a two devices with which I was not happy once due to low Akureserve and then way too strong echo / reverb. The Logitech device has not both weaknesses. I am happy.