Plantronics 81402-02 Calisto P420-M, USB Speakerphone, MOC features Advanced wideband PC audio, combined with a powerful 360-degree omni-directional microphone, reduces echo and drop-outs, greatly improving both voice and audio quality. The clarity of full-duplex audio makes communication more productive for everyone on the call and easily connects to a PC via a standard USB cable and a convenient headphone jack accommodates private calls.