... card player 12'' USB SD MP3 Wireless Portable PA Speaker System AK12-203Portable PA System Features:1. USB/SD/MMC/MMS ... . 7. 6.3mm wired mic jack System specifications : Wireless PA System Speaker4 Ohm 12 Inch Woofer Frequency Band VHF ... Scope: *Room, outside(especially suitable dancing, gymnastics, demonstration's loud-speaker, recorded, play) *Teaching, Conference, classroom, military training, guide ...