The Honeywell 16 in. x 24 in. Allergen Plus Pleated Filter is made of a self-supported pleated media. The unique filter construction requires less energy to help you save more money. Its electrostatic charge and large surface area of pleated material improve the efficiency of its dust-holding capacity. Housed in a recyclable, clay-coated, moisture-resistant frame, this filter captures particles as small as 1 micron (in comparison, a human hair is approximately 150 microns in size). This filter is effective against microscopic allergens, bacteria, disintegrated feces, tobacco smoke, insecticide dust, lead dust, mold spores, pollen, pet dander, nuisance dust and dust mite debris.