Logitech Expansion Mic for Group (2 Mics)

HEAR CLEARLY UP TO 28 FEET
GROUP Expansion Mics feature a voice pickup range up to 28 feet (8.5 meters), so everyone's voice can be heard. Simply plug the microphones into the GROUP speakerphone-they are automatically recognized and configured.

EASILY MUTE CALLS
A microphone mute button lets those at the far end of the table mute the entire speakerphone system. The indicator light shows when the microphone is muted, when a call is active, and when Bluetooth wireless pairing has begun.

Logitech Expansion Mics 989-000171 

Logitech Expansion Microphones extend the range of the GROUP video conferencing system and comfortably allow up to 20 people to collaborate in one large room. Participants no longer need to huddle around the speakerphone.