Size:12x24x1 ﾂ?|ﾂ? Unit Count:2 As you manage your allergies on a day to day basis, you're looking for options that can help reduce allergens in your air. Filtrete Allergen Reduction filters turn your central heating and cooling system into a whole house air cleaner. With electrostatic technology, these filters help reduce airborne allergens from air passing through the filter.