[Reduce Noise] The acoustic panels groove 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 [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-. It's also durable and is designed to last for a long time [Expands Quickly]Our sound absorbing panels come compressed in a vacuum package and quickly recover to normal size, soaking the foam in water for 3 minutes then wringing the water out and using a hair dryer or letting it air/sun dry for 24 hours Easy to Install - The back of each board of sound proof foam panels is already covered with glue, you just need to tear the kraft paper and , easily adheres and hold strongly on a of indoor surfaces. No special tools or materials are needed for installation. Easy to shape and cut to size. [Widely Use]Great for spot treating sound on walls in your studio or home entertainment theaters,recording studios, podcasting, vocal booths. Easy to shape and cut to size, altering 't affect performance. Colour:black Material:Polyurethane Size:30 x 30 x 5cm Package Contents: 12 * Acoustic Foam Panels 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.