Usage Tips:Professional Acoustic Treatment - The ly designed shape provides a larger sound absorption area. Therefore, they effectively reduce reverb, flutter echoes, undesirable acoustic reflections, unwanted noises. Improve Sound Quality & Clarity - Acoustic foam panels are used to control the reverberation sounds make and this is quite different from soundproofing. it can reduce the in the room, improve the sound quality and stereo imaging. Perfectly good for video, audio recording, meeting, podcast, live, music studio, and gaming room. Quick Recover to Normal Size - The soundproof foam comes compressed in a vacuum package, you need to place in a well ventilated place for about 2 hours. If part of the acoustic foam can not fully expand, you only need to soak it in water for 3-5 minutes, ventilate it to dry for about 24 hours, will be to expand to the normal size. Note:With adhesive backing, the color and style of the adhesive backing are random and cannot be specified. Colour:Black Material:Polyurethane Size:30x30x2.5cm Package Contents: 12 * Acoustic foam 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.