It is porous material and the enormous micro holes are made up of fiber. The sound wave will be reflected party after its striking on the material surface. The sheet materials absorb some sound waves; others enter the back cavities by crossing the sheet material then lower the sound reflection greatly. Thus, it lowers the noise by controlling and adjusting the indoor echo time. This product series are suitable for the public facilities and place, cultural and recreational place, sport place, hotel and shop environments etc.