Frequency Range: VHF/FM 109-120MHZ Frequency Respone: 100-10000hz(±3db) Dynamic Range: 80db Singal Rate: >80db General Distortion: ≤0% Working Temperature: 0℃---45℃ Working Range: 30 meters below the perfect condition Transmitter: type: FM(The rate is not disturbed when two mircophones emiss synchronously) Output power of Emission: 8millipower(max 50milliohm) Warp of Frequency: 30KHZ receiver: type:FM(can receive two different frequency singal synchronously) receiving type: exceed outer wave sound wave output:25mv(mixed output) output impedance: 600ohm(unbalanced) Delicacy of Receiving: 30dBuV antenna: outside pole antenna Working Voltage: 220v 50Hz 或110v 60Hz (according to clients' demands); 9vcascading batteries