iMicro SP-IMTP331 Headset With Microphone iMicro SP-IMTP331 Multimedia Stereo Headphones General Features: Black color Goose Neck Boom Microphone Speaker Driver Unit: 40mm Speaker Frequency: 20~20kHz Speaker Sensitivity: 110dB 3dB Speaker Impedance: 32ohm 15% Mic. Dimension: 6 5mm Mic. Frequency: 20~20kHz Mic. Sensitivity: -58dB 3dB Mic. Impedance: 2K ohm