18x20x1 (17_1/2x19_1/2) Pleated Air Filters MERV 14 Plus Carbon 24 Pack
There is an airflow direction arrow on the side edge of your Nordic Pure pleated air filter. For air filters with carbon added the carbon is on the air exit side. It will help eliminate unwanted odors as well as trap most airborne dust and particulate matter for fresh, clean air.