How to restore acoustic foam to its normal size: 1. After opening the vacuum pack, place the acoustic foam in a ventilated place for 12-24 hours. 2. Alternatively, soak the foam in water for 1 minute, wring it out, and then air dry or use a fan. Low-cost noise reduction solutions: These cost-effective noise reduction products create an excellent listening or recording environment, allowing you to enjoy a great recording experience at home or in the studio. High-density flame-retardant material: The sound-absorbing foam panels are made of flame-retardant and environmentally friendly materials, making them safe to use. Ideal for professional acoustic control, sound dampening, acoustic treatment, and noise reduction – reduce waves, reverb, and flutter echoes in small to medium-sized rooms. Installation method: It is recommended to attach tape to the four corners on the back of the acoustic foam panels and then stick them to the wall. Alternatively, you can purchase spray adhesive to install the soundproofing foam as needed. Multi-functional use: Perfect for acoustic treatment/isolation shields in home theaters, studios, or game rooms, or as a privacy panel for desks in offices. Also ideal for recording studios, home theaters, and karaoke rooms. Can be applied to walls, ceilings, doors, etc. Color: black Material: polyurethane Dimensions: 12x12x48cm Package contents: 4 x sound-insulating 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 to be slightly different from the real thing. The allowable measurement error is +/- 1-3 cm.