2" x 12" x 12" GREEN/CHARCOAL Acoustic Wedge Studio Soundproofing Foam 12 Pack Pack of 12. Covers 12 sq. ft. Effective against standing waves and flutter echoes in most small-to-medium sized rooms. For use in vocal booths, control rooms and studios. Overall NRC: 0.65 Functions as a full frequency bandwidth absorber for any size room when used in conjunction with corner bass absorbers and male/female broadband absorbers. Made in U.S.A.