sound proof foam panels are made of environmentally high density polyurethane foam, fire retardant and non-. Professional sound-absorbing foam, safe to use. These egg crate foam padding is great for reducing unwanted echoes, reflections, noise in recording studio or music room. Specially designed for recording engineers and musicians as the sound listens less harsh and more focused after installing these sound foam panels on walls or ceilings. They are not for soundproofing unless you install a mass of them they will help stopping noise from escaping outside but can't completely block noise. Specially designed as Egg-crate shape, increasing the contact area with sound, does a better job in controlling echoes, standing waves and reverberation. They are widely used in recording studio, home theater, game studio, meeting room, concert hall, rehearsal room, school, facilities, musical instrument, podcast, etc. What makes our egg-crate acoustic panels unique is that they regain full shape and size very quickly, usually within 12 hours but sometimes may take . You 't see any worry for the panels to puff although they comes vacuum sealed package. Just remember to separate these panels and let them sit in a well ventilated place and they will fast be what you want. If the corner of the foam didn't restore well, pls try water-soaking for 1mins, wring out and air dry. Colour:black Material:Polyurethane Size:Side length: 17.5cm Package Contents: 12 x Soundproof Foam Only 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.