Waterproof shouting distance audio surveillance Microphone, Directional,Monitor distance: 5m Size 30mm*50mm, Weight 120g ******* ... ********F.TRADIO outdoor waterproof, shouting distance,directional audio surveillance mic,special design for ourdoor talkback, toll booth ... -intensity sounds, reliably protecting the back-end audio surveillance equipment* Low noise,low echo and clear speech,suit ...