It is a device capturing and controling all the signals, which are being created by the whole system, especially the made and received phone call signals. The device is mostly used for connecting regular phone system with the Internet and backwards.
The Blackwire C620-M by Plantronics is a USB binaural headset that was optimized to work in conjunction with Microsoft Lync. With its inline volume controls and support for wideband audio, the C620-m is designed for comfortable pleasantly fitting all day use.