speaker box,professional speaker 1.speaker sensitivity high 2.grinds sand material 3.MP3,CD,PC input 4.pa loudspeaker pa loudspeaker(K218-A)FEATURES:1.speaker sensitivity high2.grinds sand material3.MP3,CD,PC input4.pa loudspeaker1. It uses imported unit and strengthen of power output.2. It has outstanding sound quality and perfect safeguard function.3. Application :classroom, conference room, ...