-friendly and SafetyMade of high quality environmentally polyurethane foam, these studio foam are durable and effective, no health risks, safe to use. Noise Absorbing sound foam panels can dampen and diffuse mid to low frequency sound waves inside of a room, to minimize interference, increases increasing sound . Easy to InstallThese studio sound absorbing panels can be used as acoustic cover for walls, ceilings and doors, just easily attach it with , , screws, tacks or glue. Widely Usage sound dampening foam panels are great for recording studios, vocal booths, control rooms, also perfect theaters, professional theaters, concert and more. 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 colour: black + red Material: polyurethane Size: 30x30x2.5cm Package contents: 25 * black sound-absorbing cotton 25 * Red sound-absorbing cotton Warm Tips: Foam will not deteriorate or apart over time, all that you need to do is to clean the dust after long time use. 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.