A high-capacity gas purifying system designed to reduce contaminants in gases commonly used in laboratory applications to low-ppb levels. The AFS Purifier III removes moisture from inert gases and hydrogen. It contains a high-sensitivity moisture indicator. When cartridge is depleted the moisture indicator changes from BLUE to BROWN. The AFS Purifier III has a very high capacity and can be expected to supply four GC's for at least one year when used with 99.995% pure gas supplies (provided reasonable care is taken during tank changes). The Advanced Filter System Complete Kit includes the AFS Cartridge, Manifold, and the wall and bench mounting brackets.