Clear The Air's Trion "Air Bear" Merv 13 filters are the best possible choice in residential HVAC filtration. Hospital-quality, advanced pleated technology, our Green pleat is a cost effective means of upgrading your air quality, while maintaining low pressure drop and long service life. It removes 96% of allergens, fine particles, dust, pollen, dust mites, bacteria, mold spores, pet dander, smoke, gases & odors. This filter is the ideal choice for asthmatics. Clear The Air's Trion "Air Bear" Merv 13 filters are available in 4 sizes. Please see the technical specs of you are unsure of the size you need. Clear The Air replacement Trion "Air Bear" filters are electrostatically charged 100% synthetic graduated density media is continuously bonded to a 30 gauge galvanized, corrosion resistant, expanded metal support grid with an effective open area of 96%. The media is resistant to a wide range of chemicals, does not absorb moisture and will not support microbial growth. The controlled pleat spacing maximizes surface area and dust holding capacity and is bonded to the enclosure frame to prevent dust bypass. The enclosure frame is constructed of high wet strength moisture resistant beverage board. The diagonal support members of the frame are bonded to the entering and exiting apexes of each pleat to prevent pleat collapse and filter bowing.