S4 panel is an economical and easily cleanable sound absorber. The S4 panel is constructed from a 3 PCF fiberglass core completely encapsulated with a fiberglass reinforced, aluminized polyester film facing. S4 is available in 1″ and 2″ thicknesses and panel sizes up to 48″ x 120″. The S4 panel with aluminized (silver) facing can be used in temperatures from -65° F to 265° F.