20x24x4 (3 5/8) Pleated MERV 13 Air Filters 6 PackNordic Pure 20x24x4 Pleated Air Filters MERV 13 are made of electrostatically charged synthetic materials that attract and capture most airborne particulates in your home. Each time air passes through a Nordic Pure pleated furnace filter, lint, household dust, pollen, dust mites, pet dander, smoke particles, smog, virus carriers, bacteria, mold spores and other contaminants are removed. All Nordic Pure pleated air filters are manufactured using a