Clearsonic S2216 Sorber twin-pack - Absorber Panel, constructed from Fiberglass encased in heavy-duty dark gray cloth. S1 Absorber can be attached to the inside of the ClearSonic Panel to reduce the amount of reflected sound, or attached to a wall to improve acoustics in a room. They are hook and loop-receptive and easily attached to almost any flat surface. 16" H x 22" W x 1.5" D., Color: Dark Gray., 2-pack