700 Series insulation board is made with inorganic glass fibers and a thermosetting resin binder formed into flexible, semi-rigid or rigid rectangular boards.  They are available in plain and faced form in multiple densities and thicknesses.  They are used to insulate ductwork, equipment, vessels, chillers, etc.- they are not designed for use on the interior of ductwork or anywhere that the insulation will be exposed to an air stream.