[-ADHESIVE,NO TOOLS REQUIRED, Easy to Install]No extra money is needed to buy glue,the back of each board is already covered with glue, you just need to tear the paper and . (Please make to press each place on the block to make the sticking more .) Achieve the sound absorption and reflection with 2-inch thick pyramid-shaped soundproof wall panels, achieving maximum surface area for the utmost sound control. Easy to shape and cut to size, customizing the shape you like and 't affect performance. The soundproof foam are made by polyester fiber, odorless, non-toxic,formaldehyde-free and have thousands of pores inside, which makes breathable and moisture-proof. While the room dry and safe to in and touch. Perfect for individuals to reduce and unwanted echoes, waves, reverb, and flutter echoes. Reduce echoes and increase musical . Perfect to use learning room, gaming room, recording studio, theaters, concert and more. size: 30 x 30 x 5cm Material: Polyurethane colour: black+grey Package Contents: 12 x studio 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.