Opti-fiber media with low pressure drop characteristics 75% minimum average efficiency 1 to 3 microns Replacement media 6FM2025 (GFI #4551 - MERV 11) or 5FM2025 (GFI #4501 - MERV 10), (change every 6 months) 22 gauge, galvanized cabinet with metal door 10 or 12 x 26-1/2 in adjustable inlet duct opening Furnace opening adjusts from 19 or 22-1/2 x 26 1/2 in Solid cabinet Made to fit 1.3 or 3.5 ton electric air handlers or gas furnaces Removes dust, dust mites, pet dander, pollen and more, airborne particulates as small as 0.01 microns Space saving design for vertical installations, keeps furnace off floor, allowing a clean, professional installation Two pull-out doors allow easy access for filter changes Eliminates the possibility of dust, pet hair, insects, rodents, water or sewer backup from entering the furnace Hydrophobic (resists moisture) filter media New filter platforms by GeneralAire® offer the most well-built, sleek designed and easiest to use galvanized sheet metal filter housings on the market Allows furnace to work at maximum efficiency and extends life of furnace by providing even air flow distribution across bottom Especially ideal for High Efficiency Furnaces, where side returns require more installation time and are inefficient compared to a bottom return Allows filter to work at maximum efficiency by eliminating need for transitions deflectors or turning vanes, thereby saving installation time and costs Made to fit 1 to 3 ton or 3.5 ton electric air handlers or gas furnaces Ideal for homes with allergy, asthma or respiratory sufferers, smokers, pets and mustiness Helps protect and prolong the operating efficiency of the heating and cooling system

ANSI/ASHRAE 52.2-1999