NOTE - We recommend leaving the product in a ventilated place for 3-4 days after receiving it. It needs to be spread out one by one so that it is fully exposed to the air, and then it can be opened to a certain thickness and finally it is ready for use. HIGH DENSITY - These acoustic panels are made from polyurethane flame retardant material, safe, sound-absorbing, and durable. Foam density is more than other similar products, to be both aesthetically pleasing and functional. WEDGE SURFACE - The wedge surface of 12 grooves is deeper and thicker than other shapes that dampen echo and bounce back from a corner or a wall. The best choice for the recording studio, control room, office studio, home entertainment theatre, home office. SELF ADHESIVE - Each sound proofing panel comes with flat sticky strips on the back for quick and easy attachment to the wall. They are lightweight enough to be very easily secured to any wall or surface, bringing an artsy feel to your home, office and studio. THICKENED PRACTICAL - The package contains 12 pack sound absorption wall panels, the size of the sound absorbing panel is 30 x 30 x 5 cm /12 x 12 x 2 inches. If you're trying to silence y