Spracht ZM DECT 6.0 Wireless Conference Call Headset with Base Station Secure DECT 6.0 Protocol headset with built in recharger base station. Use over the head 'headgear' or ear hanger. Active DSP noise cancellation microphone. Full Duplex for simultaneous conversations Conference multiple Headsets simultaneously. Both 3-way and conference calling. Low Emissions - Dynamic signal power adjustment. Adjusts for lowest emissions based on proximity to base station. Li Ion Polymer battery-LED battery level indicator. 3-hour charging time. DECT/GAP/VOIP-compatible. Standby time is up to 120 hours. Talk time up to 7-hours. 492-feet aoperating range.