This can be a case of 6 pieces of 24 x 48 x 2 inch Rockboard 80 manufactured by Roxul. It’s rigid mineral wool board with a density of 8 pounds per cubic foot. Rockboard 80 is a brilliant option for acoustic projects that require a rigid subject matter. It is also utilized in a few bass entice designs.
8 pound per cubic foot density
Rigid mineral wool board
Widespread for bass traps and other acoustical merchandise