DeanKe Hands-free Wireless FM Condenser Microphone Headset Megaphone Mic for Tour Guide, Salesman, Teaching,Speakers,Host (Black) High-definition digital tube display frequency, makes operation more easy and convenient The built-in polymer battery, not only can be used repeatedly charging, and light weight use safety Super multi-channel optional, will not interfere with each other 200 optional channel Small and exquisite, portable, amplification function anytime and anywhere Widely used: teaching, tour guide, sales promotion, lectures, meetings, karaoke, fans singing and so on purpose