Auralex 4SF24ORA 4 Studiofoam Wedge Panels in Orange 6-2'x4'x4 panels Anechoic wedge cut offers superior sound absorption Effectively reduce standing waves and flutter echoes as well as provides low frequency absorption Won't crumble with age Absorbs up to 60% better than other brands with an NRC of 1.10 Class B Fire Rated