Specification Speaker size: 50mm Impedance: 20 ohms plus or minus 15% Sensitivity: 119 plus or minus 3dB Frequency range: 20Hz~20KHz Microphone: 6.0x2.7mm Microphone sensitivity: -38 plus or minus 3dB Microphone Impedance: 2.2k ohms Directionality: omnidirectional LED working voltage: DC5V plus or minus 5% Headset jack: 3.5mm