Poly Savi 8240 UC MS USB-A Convertible Wireless DECT Headset System - Speaker Size: 32mm - Frequency Response: 100 ~ 6800Hz (Wideband), 20Hz ~ 20kHz (Media) - Speaker Impedance: 32 ohms - Microphone: Noise-cancelling - Battery Life: Up to 7 Hours Talk Time, 30 Hours Standby - Wireless Range: Up to 180m (Line of Sight) - Wireless Connection: DECT 6.0 (D200 USB-A Adapter) - Wearing Style: Convertible - Microsoft Certified - 211201-02 - 12 Months Limited Warranty