Product Feature 

20ft(6m) voice pick up range. Remarkably rich and crystal-clear voice quality for large conferences (10-25 participants in a room of 40-100 Square meters).
Full-duplex bluetooth speakerphone with DSP, everyone can hear and be heard in sound that's crisp and clear. 
Beam-forming Technology --- With 4 built-in omni-directional mics.
Noise reduction technology --- Ambient noises and other distracting tones are suppressed to support comfortable, natural-sounding conversation on both ends of the call. 
Enjoy crystal clear voice calls with DSP Technology --- Excellent full duplex bi-directional conversation and noise cancellation function. 
2pcs Expansion Microphones 
Optional Accessories --- Expand the conversation area from 6m/20ft to 10m/33ft. High sensitivity omnidirectional microphone provide 360 degrees audio pickup. Everyone can hear more clear and highly intelligible. 

Product Parameter 

USB 2.0/Bluetooth./2.4g wireless. Acoustic Ech Echo length cancellation: ≥400ms. 
Bidirectional noise compression (NC): <25dB. 
Automatic gain control (AGC). 
Microphone frequency response: 100Hz-22KHz. 
Automatic Direction finding Technology of Intelligent microphone (EMI).  
Speaker frequency response: 100Hz-22KHz. 
Speaker volume: 95dB at the most. 
Expansion Mic (optional): 2 external microphones optional for connection makes the sound-pickup diameter up to 10 meters.
Dimensions: 200mm*200mm*52mm (L*W*H). 
What's in the box. 
Speakerphone, USB cable (3m), manual, 5V adapter, 3.5mm audio cable.