Features: Single or dual channel wireless receiver Wide frequency responds High precision "Quartz crystal locked" frequency technology Noise Resistance, limits noise output Super silent function, low T.H.D. Blue LED meter display. RF signal indicator AF indicator Volume control for both channels 2x high gain telescoping antennas. Silent ON/OFF switching function (protect amplifier and speakers) 2 Balanced output XLR connectors 2-way channels designed. 2 mic can be using at the same time close or far apart with no interference. Rack-Mountable (brackets included)   Specification: Comprehensive Performance: Carrier Frequency VHF 170MHz / Frequency Stability Less Than ±30ppm Dynamic Range More Than 90dB Total Harmonic Distortion Less Than 0.5%, 40Hz-15Khz ±3Db Frequency Response Separate Type: 0~±400Mv Audio Output Level: 0~200mV Receiver: Power Supply AC 110V 50/60Hz Consume POwer 4 Watt Signal/Noise Ratio More Than 90dB Image & Spurious Rejection More Than 80dB Border Upon Sensitivity 10 dBuV (SINAD= 30dB) De-Emphasis 50us Microphone: Trasmitter Power 8.5Mw Modulation Type FM, F3F Mas Deviation ±25Khz Spurious Emission More Than 40dB (with carrier) Battery Voltage 9V/3V Continous Usage 6 Hours