This product, the CeTech Carbon Paper GDS210-H, is designed as a gas diffusion layer material for electrochemical energy devices such as proton exchange membrane fuel cells and electrolyzers. Manufactured with a controlled thickness and porosity, it offers balanced electrical conductivity and gas permeability essential for efficient reactant transport and current collection. The standard sheet size of 20 cm × 20 cm facilitates straightforward integration into laboratory-scale testing setups or small stack assemblies. The carbon paper features a rigid, macroporous structure that provides mechanical support while minimizing mass transport resistance. Its properties make it well suited for evaluating catalyst layer performance or optimizing water management in low-temperature electrochemical systems. This material is commonly used in research environments requiring consistent, reproducible diffusion media.