Filtrete 20x24x1, Furnace Air Filter, 1900, Healthy Living Ultimate Allergen, 6-Pack (exact dimensions 19.81 x 23.81 x 0.78)

62% , like bacteria and particles that carry viruses ( % captured is based on 52.2 testing for 0.3 to 1-micron particles from the air passing through the filter, which relates to industry-standard efficiency testing) as asthma & allergy friendly (As outlined in report : 1246-01) : 1900 available in 4 in., 4 in. slim fit, and 5 in. thick air filters A dirty filter will slow down air flow and make the system work harder to keep you warm or cool - wasting energy.