Driver Unit: Φ40mm Speaker Impedance: 32Ω Speaker Sensitivity:89?dB Speaker Frequency Response: 20?0000Hz Maximum Power Input:30mW Microphone Size: 6.0x5.0mm Microphone Sensitivity: -42dB?dB Microphone Frequency Response: 20?6000Hz Microphone Operating Voltage: 4.5V Microphone Impedance: ≤2.2K SNR: >58 dB Cord Length: 2.2M