ENVIRONMENT FRIENDLY AND HEALTHY: Reduce indoor echo interference and improve the quality of sound. FIRE AND FLAME RETARDANT: Sponge products, dust-free, with flame retardant function. HIGH-DENSITY: High density and high resilience. CLOSED CELL STRUCTURE: Prevent penetration of water vapor and prolong the service life. GOOD SOUND INSULATION: Interior is filled with small voids and semi-open hole structure, which enables it to absorb larger sound waves to achieve sound attenuation effect and reduce the interference and echo of sound waves reflected in the room. High quality Easy-to-use environmental friendly polyurethane foam Acoustic quiet and noise control can be used to limit unwanted noise. Soundproofing can suppress unwanted indirect soundwaves such as reflections that cause echoes and resonances that cause reverberation. Therefore we have this sound proof that can be able to limit it from 57hz to 20khz recommended. Key Features 1. Fire Retardant 2. Eco-friendly 3. Easy to install 4. High density 5. Sound Absorbing How to use: Our acoustic foam comes compressed. Place it in a ventilated place and wait for 2-3 days for it to return to normal size. If the shape recovery is not good, spray water on it and wring it, and let it sit for 3-4 hours. Stick a double sided tape on all four corners and the center of the foam, then stick it on the wall. Product Description Model: Pyramid shape Color: Black, Red, Blue, Grey Materiel: High quality environmentally polyurethane foam Size: Size 30*30*5cm (12"*12"*2") Note: Colors may look different due to lighting.