[SELF-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 stick it on the wall. (Please make to press each place on the block several times to make the sticking more firm.)Achieve the sound absorption and reflection with our 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 won't affect performance.The soundproof foam are made by polyester fiber, odorless, non-toxic,formaldehyde-free and have thousands of tiny pores inside, which makes them breathable and moisture-proof. While keeping the room dry and safe to breathe in and touch.Perfect for individuals to reduce and absorb unwanted echoes, waves, reverb, and flutter echoes. Reduce echoes and increase musical inspiration. Perfect to use for home learning room, gaming room, recording studio, theaters, concert and more.size: 30 x 30 x 5cmMaterial: Polyurethanecolour: black+greyPackage Contents:12 x studio foamOnly the above package content, other products are not included.Note: Light 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.