The AltairAquila range of filter elements consists of the cleanable PFA pre-filter and three disposable high efficiency bag filters. All three high efficiency elements are interchangeable and offer superior coalescence performance with or without pre-filters. Features & Benefits PFA The cleanable PFA pre-filter is used in medium or high particulate environments to increase the dust holding capacity of the system and the life of the high efficiency filter elements. HEA The HEA is the entry-level filter element, offering excellent filtration efficiency with the added benefit of very low pressure loss. HXA The HXA offers an increased level of efficiency, particularly for smaller contaminants. It is ideally suited for users who need a longer interval between compressor washings. HVA For even higher removal efficiency, including superb sub-micron performance, the HVA filter element is the ideal choice.