Acoustic Foam Normal Size Preparation: 1. After opening the vacuum pack, place the acoustic foam in a ventilated area for 12-24 hours; 2. Alternatively, soak the foam in water for 1 minute, wring it out, then air dry or use a fan. Sound Isolation Principle: The sound-absorbing foam works by repeatedly reflecting sound waves within the sponge, achieving noise reduction and sound absorption. These acoustic panels are effective and harmless. The high-quality studio foam maintains its soundproofing capabilities permanently. Simply vacuum or dust occasionally for cleaning. High-Density Fire-Retardant Material: Made from fire-retardant and eco-friendly materials for safe use. Features a broad absorption spectrum above 500Hz and a high-density material exceeding the industry standard by 30%. Improves sound quality by absorbing harmful noises, reducing fluctuations, reverberation, and vibration, resulting in clearer, more useful sound. Easy Installation: We recommend attaching tape to the four corners and the center of the back of the acoustic foam panels before mounting to the wall. Alternatively, use spray adhesive for installation. Professional Acoustic Control: Each acoustic foam panel arrives uncompressed and in prime condition. Achieve professional acoustic control, sound dampening, acoustic processing, and noise reduction. Perfect for reducing waves, reverb, and flutter echoes in small to medium-sized rooms. Ideal for sound recording studios, rooms, home theaters, KTV, and public spaces. color: Black+gray Material: Polyurethane size: 30 x 30 x 2.5 cm Package Contents: 12 x Black sound insulation foam 12 x Gray sound insulation foam 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.