Logitech H820e. Purpose Call center/Office. Headset type Monaural. Wearing style Head-band. Colour of product Black. Connectivity technology Wireless. Wireless range 100 m. Ear coupling Supraaural. Headphone frequency 150 - 7000 Hz. Headphone sensitivity 103 dB. Microphone frequency 100 - 7000 Hz. Microphone sensitivity 45 dB