The AltairSystem2 range of filter elements consists of the cleanable PBR pre-filter and a range of high efficiency filter options. The high efficiency elements are interchangeable and offer superior coalescence performance with or without pre-filters. Features & Benefits PBR The cleanable PBR 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. HVL The HVL is the entry-level filter element, offering excellent filtration efficiency with the added benefit of a very low pressure loss. HVX The HVX offers an increased level of efficiency, particularly for smaller contaminants. HVS6 The HVS6 offers higher dust retention than the HVX. It isideally suited for users who need a longer interval between compressor washings. HVV For even higher removal efficiency, including superb sub-micron performance, the HVV filter element is the ideal choice.