... bluetooth MIC 3.sensitivity:86db 4.property:2.4G MIC built in wireless handheld microphone Function:1.It has more than 1000 ... .The same transmitter can be used on different receiver.3. Built-in MIC design,eliminating the line.4. Staff of a small ... power supply,low battery,signal link,volume and so on.6. Remote electronic laser pointer,page turner, USB upgrading.7. Pen ...