The powerful HEPA-AIRE model H2000L and deluxe model H2000LA Negative Air Machines from Abatement Technologies are designed for the contractor who wants the very best in performance, reliability and quality. The difference between the two units is that the H2000L is equipped with a visual “change filter” indicator lamp, while the H2000LA deluxe model adds a large 5” diameter magnehelic pressure-gauge and an audio “change filter” alarm.