A t-coil induction neckloop with Bluetooth transceiver has a built-in microphone and replaceable rechargeable battery. Hands free connectivity to your cell phone or computer. Wireless computer CD/DVD audio and VOIP communications such as Skype. Volume control for amplification. Comes with USB battery charger and car adapter. Use rechargeable (included) or alkaline AAA battery. Talk time up to 15 hours. One year warranty.