Soundproofing - Acoustic foam panels triangular grooves structure for better noise absorption, helps to reduce and absorb unwanted echoes, waves, reverb and flutter echoes for better recording effect. Upgraded Accessory - Additional adhesive tape is included , which helps you the installation better and protect your walls from damage. Can be removed easily. Quick Recovery - If this high-density foam doesn't return to shape, please soak it in water for a few minutes and dry in the air to recover the shape in 24 to 48 hours. Wide Applications - Suitably used not only for spot treating sound on walls in your studio and office but also for use in recording studios, vocal booths, control rooms. Professional Safe - With strong fire resistance and good air permeability, the acoustic foam panels can stop burning to prevent hidden fire hazards. Also, non- materials 't do harm to your body while everyday use Colour:black Material:Polyurethane size:30x30x2.5cm note:With small adhesive backing, the color and style of adhesive backing are random, don't accept the specified color and style Package Contents: 52 * acoustic panel 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.