Acoustic Foam 1" Thick Pyramid Style 4ft X 6ft (24 Sq Ft.) B-Stock NRC Rating: 0.35 Size: 4ft X 6ft (24 Sq Ft.) Sheets Color: Charcoal ; 2 lb Density ; Made in the USA Effective on mid to high frequency ranges Meets ASTM E84 Class A and California 117 flame retardancy specifications.