This product is designed as a carbon paper featuring a hydrophobic microporous layer, commonly employed as a gas diffusion layer in electrochemical devices such as fuel cells, water electrolyzers, and carbon dioxide reduction systems. The substrate incorporates a 5% PTFE coating on the surface, while the microporous layer contains 20–25% PTFE, ensuring strong water repellency with a water contact angle exceeding 130°. This hydrophobic treatment enables efficient gas transport and liquid water management under operational conditions. Available in a sheet size of 23.5 × 20 cm, the material is suitable for laboratory-scale electrode assembly and research into zinc–air batteries, proton exchange membrane fuel cells, and related energy conversion technologies. Its balanced permeability and mechanical integrity support reproducible experimental results in advanced energy material studies.