Reduce noise: The 2-inch foam-designed acoustic panel reduces wave amplitude by increasing air resistance and absorbing sound. Effectively controls mid to high frequencies. Quickly unfold: 12 panels per set. The soundproof foam is vacuum compressed and should be placed in a well-ventilated area. It will fully expand within 24–72 hours. Fire retardant & environmentally friendly: The sound insulation foam is fire retardant, helping to prevent the spread of flames. Made without formaldehyde. Durable construction with long-lasting design. Helps reduce echoes. Easy to install: Lightweight sound insulation foam panels can be installed on various surfaces. No tools required. Note: Double-sided tape or adhesive is not included and must be purchased separately. Widely used: Ideal for improving sound quality on walls in studios, offices, recording studios, control rooms, home studios, home theaters, conference rooms, nurseries, and more. Color: White Material: Polyurethane foam Size: 30 x 30 x 5 cm Package Contents: 12 x Sound-absorbing foam panels Only the above contents are included; other items are not included. Note: Lighting and display differences may cause slight color variation between the image and the actual item. Measurement error allowance is +/- 1–3 cm.