http://www.meeteasy.com.hk/2016/06/15/mvoice-1000-b/

Model：MVOICE-1000-B

3 built-in microphones can be controlled separately
DSP noise and echo cancellation
USB and analog interface for high-quality audio calls on PCs or laptops
Compact design for easy carrying around

Feature:

3 high sensitive microphones provide 360° audio pickup over 3 meters. 
-USB connection to PC for web-conferencing and Video conferencing. 
-Bluetooth built-in for conference calls via cell phone. 
-Excellent full duplex bi-directional conversation. 
-Echo cancellation eliminates acoustic echo. 
-Noise cancellation removes ambient room noise. 
-Advanced DSP technology delivers remarkably rich, crystal-clear audio. 
-3 Microphones can be controlled separately for specific conference situations. 
-Full spectrum speaker for outstanding audio output.