Spectracarb gas diffusion layers (GDL) papers and panels consist of graphitized resin bonded carbon fibers that form porous sheets, with high electrical / thermal conductivity and chemical / corrosion resistance that control the proper flow of reactant gases (hydrogen and air) and the water transport in the membrane electrode assembly (MEA).  Spectracarb is manufactured and owned by Engineered Fiber Technology (EFT), LLC.

The main efforts of the production of Spectracarb have focused on specialty processed thin papers and laminated multi-ply panels, with a wide range of densities and thicknesses ranging from 0.25 g/cm³ and one-tenth of a millimeter to 0.90 g/cm³ and four-millimeters, respectively. All Spectracarb GDL products are made in the USA.