CS540 convertible over-the-head or over-the-ear. Hands-free productivity. Outstanding audio quality. Conference with up to three additional headsets. Power-saving features. Energy efficient adaptive power system optimizes for range and talk time. Pair with a base unit by docking the headset, enabling quick setup in hot-desk environments. Use with Electronic Hookswitch Cable or Handset Lifter to remotely answer/end calls. Talk time: Up to 7 hours. Earpiece weight: 22g. Range: Up to 120 metres. For further information please call the Plantronics helpline on 0800 410014. Check compatibility at http://www.plantro.net/en/compatibility.html.