iMicro IM320 USB Headset Speaker Diameter: 40 mm Speaker Frequency: 20 ~ 20 KHz Speaker Impedance: 32ohm  15% Speaker Sensitivity: 110dB  3dB Microphone: Mic Diameter: 6.5 mm Mic Sensitivity: -58dB  2dB Mic Impedance: 2.2Kohm  15% Cord Length: 2200 mm