Reduce noise: The 2-inch foam acoustic panel reduces sound wave amplitude by absorbing sound energy. Effectively controls mid to high frequencies. Quickly expands: 12 panels per set. Soundproof foam is vacuum-compressed and will return to full size within 2472 hours when placed in a well-ventilated area. Flame retardant and environmentally friendly: Acoustic foam meets fire safety standards and is made from materials that do not contain formaldehyde. Durable design helps reduce echoes. Easy to install: Lightweight panels can be mounted on various surfaces. No special tools required. Note: Double-sided tape or adhesive is not included and must be purchased separately. Versatile use: Ideal for use in recording studios, home studios, offices, control rooms, home theaters, conference rooms, nurseries, and other spaces requiring sound absorption. Color: White Material: Polyurethane foam Size: 30 x 30 x 5 cm Package contents: 12 x Sound-absorbing foam panels Note: Other items not included. Lighting and display differences may cause slight color variations. Measurement tolerance: 13 cm.