Fits most major brands of Air Cleaners. High Efficiency MERV * 11 Media Filter, rated at 492 feet/minute, removes airborne contaminants down to 0.3 micron. Filter material is constructed of continuous hydrophobic polyolefin fibers that will not shred or absorb moisture. They arecellulose free and will not sustain mold growth. Unique filter design features a structured density gradient with an electret charge for higher initial and sustained efficiencyover the life of the filter. Deep, 4-3/8 inch filter contains more media material than other filters on the market. More surface area means more collection area, longer filter life and lower static pressure. Approximately 2-4 times the dust holding capacity of most filters. Filter will last up to one year in standard applications. Cost advantage over competitor filters.