[High Materials] sound absorbing foam panels crafted from fire-retardant and -Friendly material, it is safe to use in small and medium-sized rooms. High panels for better sound absorption, Reduce waves, reverb and flutter echoes in smaller to medium sized rooms. [Noise Absorbing]For professional acoustic control sound absorption and reverberation reduction. This sound foam by attenuating excess sound waves to obtain better recording effects, the Egg surface of - increases the contact area with sound waves, and the sound absorption effect is other shapes of surfaces to minimize interference, increases increasing sound . [How To The Normal Size Of The Acoustic Foam]1. After opening the Vacuum package, place the Acoustic Foam in a ventilated place for 12-24 hours; 2. Or the foam in water for 1 , wring it dry, then air dry or use a dry. [Installation ]It is recommended to stick the tape to the four corners and the of the back of the acoustic foam panels, and then to the wall. Or you can purchase spray glue to install the soundproofing foam according to your needs. [Widely used] It is widely used for spot treatment in professional concert , recording studios, home theaters, offices or rehearsal spaces, etc. You can install sound acoustic panels to your ceilings, wall, or doorway. It's easy to shape and cut to size. Changes do not affect performance. size:30x30x3.5cm Material:Polyurethane foam colour:Black Package Contents: 24 x Soundproofing Foam Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm. Have a great time shopping!