Electrostatic Filter for Home Furnaces - 19-7/8 x 21-1/2 x 1, Duraflow Filtration, Mfr#: DEF19.821.51E

This electrostatic furnace filter is a permanent filter which will last for years with proper care. The electrostatic materials we use capture dust, dirt, pollen, pet dander, allergens, pet hair, and other household irritants. The heavy duty aluminum frame with water drain holes makes for easy cleaning. These filters should be washed every 3 months, and more frequently if you have many pets. This filter’s dimensions measure 19-7/8 x 21-1/2 x 1