Model of product: G81B Unit of horn: 050mm 15% horn impedance ：200Σ Frequency response of the speaker: 20 Hz to 20 kHz Input rating: 5V === 30mA Power rating: 0.15W Sensitivity of the microphone: -38dB Signal-to-noise ratio of the microphone: ≥58dB Frequency response of the microphone: 100 Hz–10 KHz Length of wire: ≥2.1M