... /down 4,laser pointer,MP3 play 5,LCD diplay classroom wireless microphones for teacher This model microphone is a bluetooth transmitter,we ... and processor are combined in this all-in-one unit, for revolutionary, cable-free convenience.More specifications:Transmitter(Holding) Frequency Scope ... Weight: 45G Dimension: 95.5*33.5*18(mm) classroom wireless hidden microphones for teacher audio/sound system