POLY SupraPlus SDS 2490 Headset Head-band Black

POLY SupraPlus SDS 2490. Product type: Headset, Wearing style: Head-band, Recommended usage: Office/Call center. Connectivity technology: Wired. Ear coupling: Circumaural, Headphone frequency: 100 - 10000 Hz, Impedance: 150 ?. Microphone type: Boom, Microphone frequency: 150 - 10000 Hz, Microphone input impedance: 150 ?