Oil Prefilter -- removes oil mist, particulates, and entrained water.   Color-change replacement notice. Water Removial Draintrap -- removes condensed water-oil mixtures. Dual Regenerative Heatless Air Drying Towers -- reduce water vapor content; action is to regenerate its own adsorber material. Tower Switching Network -- acts with plumbing to provide timed dryer tower switching to effect regeneration. Catalyst Cartridge -- removes CO by catalytic conversion to CO2. Color Change Dewpoint Indicator -- Color change visually shows ther performance of the drying towers. Final Filter -- effects odor removal.