Filtered Cyclonic Power Units Dirt Devil® Filtered Cyclonic Central Vacuum power units feature Cyclonic Filtration TechnologyTM (CFTTM), a unique dual filtration process that utilizes cyclonic separation for primary filtration and a pleated filter for secondary filtration. Unlike central vacuum systems that rely on permanent cloth filters, the powerful performance of Dirt Devil® will not decrease as dirt accumulates. On-board canister inlet valve promotes cyclonic cleaning power. Replaceable filter provides optimum filtration and system performance. Comfort-grip dirt canister is easy to handle. Powerful, high-performance motor delivers reliable, lasting performance. Whole-house cleaning versatility with a wide selection of cleaning kits and accessories.