Driver Unit: Φ30mm Speaker Impedance: 32ohm±15% Impedance: 16ohm±15% Speaker Sensitivity: 106dB±3dB Speaker Frequency Response: 20-20,000Hz Maximum Power input: 30mw Microphone Operating Voltage: 4.5V Microphone impedance: 2.2 K Microphone sensitivity: -58dB±2dB Microphone Frequency Response: 30-16,000Hz