[Mybecca] 8 PACK Corner Block Fill Acoustic for Low Frequency Waves Studio Soundproofing, 3 x 3 x 24 Color: CHARCOAL; Best used with Acoustic Bass Traps, TriAmps, Wedges, Pyramids, HP LightWedge 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