Set of 2 - Acoustic Foam Studio Corner Block Wall Finish Acoustic 3" X 3" X 24" Color: CHARCOAL; Best used with Acoustic Bass Traps, TriAmps, Wedges, Pyramids, Eggcrates Size: 3" x 3" x 24" ; Noise Reduction: 80-90% Eliminates Standing Waves And Flutter Echoes; Reduces Unwanted Reflections; Reduces Unwanted Reflections Good for studios, recording studios, vocal booths, control rooms. Product Care: Occasional Vacuuming of Dust