... for pcs 3,passed ISO,CE,Certificate e PROFESSIONAL WIRELESS CONFERENCE MICROPHONE 1,goose neck2,-47dB±2Db3,Alone one for pcs4, ... every master system,and unit Expansion can store 180pcs Unit representative to take part in conference.2,Two Auxs conference microphone control the ... wire way.3,Alone one or for pcs microphone working at the ...