3D ACOUSTIC DESIGN: 2 inches soundproof wall panels moderate sound control on walls or ceilings. Perfect for individuals to reduce and unwanted echoes, waves, reverb and flutter echoes. ENVIRONMENTAL PROTECTION: Made up of environmentally friendly polyurethane sound foam padding at 50/lbs per yard, the sound dampening panels not only have effective sound absorption characteristics, also will not cause any harm to body. QUICKLY TO NORMAL SIZE: Open the Vacuum package, put the sound absorbing panel in a ventilated place for about 24-48 hours. Another is soaking the soundproof foam in water for one , then wring the acoustic panels out of the water, using air to dry it or using a hair dryer. You can also let simmer under the as well! WIDE USE: Great for spot treating sound on walls in your studio or office - For use in recording studios, control rooms, Offices home studios, home entertainment theaters, Home Offices. Easy to shape and cut to size, altering 't affect performance. size:30 x 30 x 5cm Material: Sponge colour: black Package Contents: 5 x Sound insulation cotton Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.