... -loading protection, Lightning proofAudio Preamp Build-inOutput connector Power+, Audio and GND Cable 3 x 0.5mm2RVVP cableVoltage DC 12V (8 ~ 20V ... copperSize 30mmx50mmWeight 120gStandard CE,FCC*******Detail Introduction********F.TRADIO outdoor waterproof, shouting distance,directional audio surveillance mic,special design for ourdoor talkback ...