Parameter: Monitoring Range                          audio surveillance distance 0-20m(60dB),30m(80 dB)transmiting distance(shield cable)   3kmFrequency Response                     20Hz ~ 20kHzSensitivity                                     -38dBSNR                                            >40dB(outdoor) ,>70 dB(indoor) Polar Pattern                                45°wide directivityDynamic Range                            90dB(1KHz at Max dB SPL)Maximum Level Input                     120dB SPL (1KHz,THD 1%)Impedance                                    600ohm (imbalance)Signal Output Extent                     2.5Vpp/-25dbMicrophone                       Directional complementary type electret condenser mic(2pcs)Special Circuit                              DSP de-noise, AGC circuitProtect Circuit                              Over-loading protection, Lightning proofAudio Preamp                              Build-in

Output connector                          Power+, Audio and Public GND    

Cable                                           3 x 0.5mm2RVVP cableVoltage                                        DC 12V (8 ~ 20V)        Current                                        33mATemperature                                 -25°C ~ 70°CColor                                            Shell's Material                            aluminium alloySize                                            142mm × 70mm× 27mmWeight                                        332g

The biggest success project: the Tian'anmen Square,Beijing

H.TRADIO outdoor 30m long distance audio surveillance mic