The advanced dual monitoring functions in these headsets offer Bluetooth connectivity for both music and making phone calls through your Bluetooth enabled mobile phone or PC. So you can listen to your music and at the same time be able to take phone calls when they come in. When these devices are connected to your Bluetooth enabled pc, they allow you to switch between taking VOIP calls and listening to music. Main 

Features include:

Supports HSP, HFP, A2DP and AVRCP
Supports SBC specified in A2DP
Compatible with most popular Bluetooth phones and a2dp enabled audio devices
Efficient power management for low-power operation
Incorporates audio playback at 16 bit, 44.1 khz for HiFi
Supports remote control features such as volume up/down, play and stop on mp3
Keys: Play, Stop, Vol+, Vol-, Fwd, Rev.
Auto switch between making phone calls and listening to music
VOIP calls with Bluetooth USB dongle connected