The three-stage desiccant unit provides the ultimate in clean, dry air. First stage centrifugal filter removes particulates to 5 microns. Stage two coalescer filters down to .01 micron. Third stage desiccant removes remaining water vapor to a dew point of -40ºF. Ideally suited for low to medium production. DAD-500 air-drying system includes three filtering units, as well as a wall mount bracket and desiccant filter change indicator. Centrifugal and coalescer units include automatic bowl drain (standard feature), so there is no need to manually drain the system. Coalescer filter includes filter change indicator. * Desiccant filter includes sight glass indicator (changes color when desiccant needs replacement).