Savi W720 (83544-01) Dect Head One intelligent headset to manage PC, mobile and desk phone calls Hot swappable battery for unlimited talk-time (additional battery sold separately) Wireless freedom up to 350-feet from your desk. Audio performance : PC + desk phone Wideband: up to 6,800 Hz One-touch call answer/end, vol +/-, mute & flash controls across devices Noise-cancelling microphone & dual ear Pieces help filters out background noise for you and the receiver