All-in-One USB Omnidirectional Speakerphone
USB + Bluetooth + Dongle
USB + Bluetooth + Dongle connection 360° Omnidirectional Speakerphone with 5 meters pickup range Built-in 4,000mAh battery with 18 hours talking time Buttons: Bluetooth, Mic mute, Volume +, Volume -, Pickup/ hang up, power Daisy chain 2 sets M400 speakerphones by 3.5mm Audio cable