The SFC downflow cartridge dust collector uses MERV 15 filter cartridges — one of the most efficient in the industry — as standard. These Protura® Nanofiber filtersare highly efficient on particles in the 0.3 to 1 micron size range and the patented filter cleaning system and nanofiber cartridge filters allow SFC systems to be designed with higher air-to-media ratios, which may reduce the size of the collector for savings in floor space. — United Air Specialists