Product Description - Squelch Control: Noise Lock - Max. Frequency Deviation: ±18kHz - Frequency Response: 80Hz-15kHz - Frequency Steadiness: ±0.005% - S/N Ratio: >70dB - Total Harmonic Distortion: <0.5% (1kHz) - Number of Channels: 2 Channels - Receiving Sensitivity: -80dBm - Operating Range: About 140m - Harmonic Interference Rate: 50dB - False Image Interference Rate: 80dB - Receiver Power Supply: DC 12V/300mA - Transmitter Power Supply: 9V Battery - Transmit Power: +12dBm±2 dBm Voice Special dedicated in supplying wireless microphone , dynamic microphone , recording microphone , conference microphone and microphone pedestal .