100% synthetic wire backed media. Craft die cut frame. MERV rating 8. 90 day filter. Effective against pollen, dust/lint, dust mites, pet dander, mold, bacteria, virus carriers. 3 Pack 20" x 20" x 1" Natural standard pleated air filter 100% synthetic wire backed media Craft die cut frame MERV rating 8 90 day filter Eff