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(R) wireless pairing has begun.