Oreck ProShield Air Purifier Truman Cell never needs replacing The 6-stage purification process cleans and re-circulates the air - pre-filter, positive charging wires, partical collection, odor absorption, oxygenator, air revitalizer Lays flat horizontally or on its side vertically The disposable Odor Absorber helps reduce common household odors and VOCs from the air passing through it Three settings, nightlight, & 3 Year Warranty