... priority switch 5. USB/SD card player 12" outdoor active subwoofer speaker box Portable PA System Features:1. USB/SD/ ... jack System specifications : Wireless PA System Speaker4 Ohm 12 Inch Woofer Frequency Band VHF 174-270MHzOutput Power ... : *Room, outside(especially suitable dancing, gymnastics, demonstration's loud-speaker, recorded, play) *Teaching, Conference, classroom, military training, guide ...