... meeting room,public security organs, procuratorial organs... E.TRADIO: Clear Speech Microphone,Omni Directional, Monitor Range 10-50sq.m, ... echo in big hall.*0.8mm pinhole design, clear picking voice.*Restraining high intensity voice automatically, protecting rear devices.*Long-distance ... , Army's department.*According with CE standard. E.TRADIO High-Fidelity,clear speech audio surveillance microphone