16 Pack - Acoustic Foam Corner Blocks 3" x 3" x 24" Finish Corners in Studios or Home Theater 16 Pack 3" x 3" x 24" Corner Blocks (charcoal only, 16 pack only) 32 Lineal Ft Finish off your 2"-3" acoustically treated walls for an ultra clean look and added sound absorption Passes MVSS-302 Flame Tests (ultra-slow burning) High .75 NRC Rating - Absorbs mids' highs'