... Class-teaching, Tour-guiding, Micro-meeting, etc.2. TFT screen display the working mode. 3. ECHO button control makes VOICE More clear ... big rechargeable lithium battery.standby time 15 hours.10. With Remote control can operate more easily11.One key shift play mold, Memory ... power, 20W*1(L+R) Battery capacity, 7.4V, 2200MADc charger,10V Picture: Radio,MP3,TF card portable megaphone speaker with vedio