... USB SD MP3Mobile and active PA system with 12" (30cm) bass driver and 100W amplifier power45W RMS speaker load (equivalent ... 31cm (W x H x D)Weight: 13.6 g Amplifier Applicable Scope: *Room, outside(especially suitable dancing, gymnastics, ... play) *Teaching, Conference, classroom, military training, guide, sales promotion, public sale's loudspeaker recorder play. *Pageant, congregation, make a speech ...