How To Recover The Normal Size Of The Acoustic Foam: 1. After opening the Vacuum package, place the Acoustic Foam in a ventilated place for 12-24 hours. 2. Or soak the foam in water for 1 minute, wring it dry, then dry or use a blower dry. High-Density Flame-Retardant Material: The sound absorbing foam panels is made of flame-retardant and environmentally friendly materials, which can be used safely. At the same time, it can also improve sound quality: by absorbing harmful sounds, reducing fluctuations, reverberation, and vibrating , Useful sounds are clearer. Low-Cost Noise Reduction Solutions: cost-effective noise reduction products can create an excellent listening or recording environment for you, you can get a good recording experience at home or in the studio. Installation : It is recommended to stick the tape to the four corners and the center of the back of the acoustic foam panels, and then stick it to the wall. Or you can purchase spray glue to install the soundproofing foam according to your needs. Multi-Function Use: It in Home Theaters, Studios or Gaming Room for acoustic treatment / Isolation Shield , or in offices as a Desk Privacy Panel. Also Perfect for in recording studios, home theaters and karaoke room.Can handle walls, ceilings, doors, etc. size:12x12x24cm Material:Polyurethane colour:Black Package Contents: 12 x Soundproofing 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.