Specification: Total Size: 30 * 30 *2. 5cm (12"*12"*1") .Effective against standing waves and flutter echoes in most small-to-medium sized rooms. Overall NRC: 0.4 For use in vocal booths, control rooms and studios. Brand New Tile Acoustic Foam Made by Imported High Quality Foam Sound-Absorbing Foam High density acoustic foam cell structure for maximum noise absorption Helps to flutter echoes and reduce excess reflections and reverberation Improves vocal clarity and acoustics of your room Ideal for use in recording studios, home theatres and karaoke room