LINQCELL GDL1500 are optimum for use as Cathode (Hydrogen Side) Current Collectors in PEM Electrolyzers. Unlike the standard thin/low density Gas Diffusion Layers (GDL) that are intended mainly for PEM and PAFC fuel cells, the Spectracarb Porous Graphite Engineered Panel Family has been specifically engineered for the special requirements of PEM electrolyzers. Features include thicker structures of from 1.5 to over 4 millimeters, and densities up to 0.95 g/cm3. These panels also have controlled compressibility to support the external forces from the assembly. In additional to several standard grades, these engineered panels can be made on a laboratory, prototype or production scale to meet specific customer requirements.