CP0164B Features Low noise design Suitable for all kinds of 3.5 plug speakers Convenient and easy to set High-fidelity recording system Specially designed for QQ， MSN， Skype and Internet chat user General Specs Model SF-920 Operating Voltage 1.5 V Frequency Response 50 Hz-16 KHz SNR  > 36dB Cable Length 2.5 m Sensitivity  -55dB ± 2dB Directivity Omnidirectional (Noise canceling) Impedance  ≤ 2.2 KΩ Sensitivity Reduction Within- 3dB at 1V Compatibility 3.5 plug speakers