Brief Decreiption Digital USB-to-headset adapter for computers Eliminates issues with soundcard compatibility. User accessible side tone Accessible call control buttons Commercial-grade design For use on Windows 2000, XP and Vista Support MS Lync, Avaya, Cisco, Aastra, Polycom, and other UC platforms. Headset Key Features: Comfortable Adjustable headband design can be positioned for optimal comfort Ultra noise cancelling microphone Flexible boom allows 350 adjustable the mic to be positioned for optimal comfort and voice transmission. Swing-away feature lets you move the mic out of the way for beverage breaks. UltraFlex TM MIC wires improve the life of boom rolling Omni directional microphone can be passed in a quiet environment, clear sound Teflon washer support increases positioning accuracy, stability and ensure optimal durability Hi-Fi audio quality with Neodymium speakers Wideband audio frequency makes more natural voice Adjustable headband can be positioned for optimal comfort Quick-disconnect feature provide an easy way to step away from the phone without disconnecting the call or even removing your headset. Acoustic shock protection circuit ActiveProtectionTM safeguards the user from the effects of an acoustic burst Quick Link(QLTM ) function can make you leaving telephone while wearing the headset Warranty: 2 years, RoHS and CE approval. Speaker 1. Unit driver: 27mm 2. Impedance 150 +/-20% 3. Frequency Response 300-3K Hz 4. Distortion: Less than 1% 5. Sensitivity: 108dB 3dB/mw at 1KHz Omni directional Microphone 6. Frequency response: 20-3000Hz 7. Impedance: 2.2k ohm 8. Sensitivity:-42dB 2dB 9. SNR: 55dB 10. Distortion: Less than 1%. Paper box size:18.5*14.5*6.7cm for one unit 10 unit/4kgs.