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 ¡À 2dB Mic Impedance: 2.2Kohm ¡À 15% Cord Length: 2200 mm