They have an egg-carton like surface, hence the name, and are a cheap way to control acoustics. The uneven surface of these acoustic shingles allows them to absorb a wider range of frequencies and sound waves, and the thicker the shingles, the more efficient they are at absorbing low frequencies. Specification: Material: Sponge size :60cm*120cm*5cm Color: black Features: soft sponge, no dust, high density; Sound effect, suitable for cinema, KTV, etc. Pyramid sound-absorbing sponge has beautiful shape and good acoustic properties, its biggest feature is: due to its pyramid shape, it provides very little diffusion, it makes your voice more dynamic. It can also be used for inner pads, pet pads, and seat cushions!