A high-capacity gas purifying system designed to reduce contaminants in gases commonly used in laboratory applications to low-ppb levels, available in two models. The AFS Purifier II removes water and hydrocarbons (>C4) from air, hydrogen, nitrogen, helium, and other inert gases. It contains a high sensitivity moisture indicator that changes from BLUE to BROWN when the capacity is depleted. Both AFS Purifier I and AFS Purifier II have 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.