Specifications: Product Name:Soundproof Foam;  Material:Polyurethane;  Size:30cm/11.81"x30cm/11.81"(LxW);  Thickness:3cm/1.18in;  Color:Yellow / Black / Blue / Red;  Quantity:4pcs/Set;     Features: Square sound-absorbing sponge with beautiful appearance and good acoustic properties. Due to its square shape, there is almost no diffusion and the effect is very good.  High-density sound absorption to reduce harmful noise -The panel helps to reduce reverberation, vibration, and undesirable sound reflections.  Easy to shape and cut to size, changes will not affect performance.  Flame retardant, self-extinguishing after 3 seconds on the open flame, reducing safety risks. But it should be noted that burning on an open flame for a long time will destroy the flame retardancy and make the sound insulation cotton burn.  Suitable for use on walls in recording studios, offices, small and medium-sized rooms, classrooms, theater rooms, etc.    Package Included: 4 x Soundproof Foams