The 4A Molecular Sieves (Regenerative) have diameter of four angstroms. 4A Molecular Sieve is widely used for air drying, packaging, circuit breakers and in pharmaceuticals. The popular desiccant in industrial applications, 4A Molecular Sieves adsorb molecules equivalent to their pore size. Used For PaintsBrakes & brakes liningDesiccant for paint, dope and foulDeep drying of air, natural gas, alkenes and refrigerantStatic dehydration of electronic element, pharmaceutical and unstable materials