20" x 25" x 1", Purple, Ultra Allergen Filtrete Filter, 3 Month Filter Is 90% Effective At Capturing Large Allergens Like Mold Spores & Pet Dander, Captures Microscopic Allergens Like Dust, Smoke & Smog, Captures Bacteria & Particles That Can Carry Viruses, Meets The Guidelines Of The American Lung Association Health House Program. MPR Rating 1500, Filter Lasts for 90 Days, Color Purple