Owens Corning 703 FRK Rigid Fiberglass Board are 24" x 48" x 2" inches in dimension. Order Single Piece quantities on this page.
Owens Corning 703 is probably the most popular material for acoustic absorption. It is typically covered with fabric and mounted on the walls in a studio, control room, or listening room. The FRK (Foil Reinforced Kraft) facing is a popular option for creating bass traps. The foil facing will reflect some of the mid to high range frequencies, but allows the low-end frequencies to pass through to the absorption material. Be sure to face the foil side toward the room, and not toward the wall or corner. If you are using multiple layers of this product, be sure that only the outer layer, that faces the room, has foil on it. Layers underneath should have the foil removed (or use regular OC703) to yield the maximum absorption.
If you need 6 pieces or more, try Owens Corning 703 FRK 2 inch Case of 6 here
For more detailed information, see Selecting the Right Acoustic Material for a comparison of these materials.