Self Adhesive - The sound proof foam panel has a self-adhesive tab covering the entire back that can easily stick to any surface. No special tools or materials are needed for installation. Easy to shape and cut to size, altering won’t affect performance | Reduce Noise - The acoustic panels designed 2 inch foam reduces the amplitude of sound waves by increasing the air resistance and absorbing it. Can be used effectively to tame mid and high frequencies | Expands Quickly - 12 pack/set, each piece is 12 X 12 X 2 inches thick. The soundproof foam comes compressed in a vacuum package and quickly recover to normal size by placing in a well ventilated place for about 24-72 hours | Fire Retardant & Eco-Friendly - The soundproof foam is fire retardant, stop fire from spreading and reduce intensity. The material used in making them is formaldehyde-free, which makes it non-toxic. It's also durable and is designed to last for a long time | Wide Use: Great for spot treating sound on walls in your studio or office, Recording Studios, Control Rooms, Offices Home Studios, Home Entertainment Theaters, Home Offices, Meeting Room, Baby Room, etc