2-Pack - Filtrete 4" Allergen Reduction Filter from 3M - 20x25x4 # DP03DC Nominal size: 20" x 25" x 4" Actual size: 19-3/4" X 24-7/16" X 4-3/16" This filter is designed to fit filter housing units accomodating 20x25x4 nominal size filters. Replaces: Honeywell filter # FC100A1037 in air cleaner models F25, F35, F100, F150, F200 Trion Air Bear filter # 255649-102 (includes 2000 series and Air Bear right angle air cleaners) This new high performance filter is 97% effective at attracting and capturing large airborne allergena like pollen, mold spores and dust mites. This carries 3M's microparticle rating of 1550 (approximately equivalent to MERV 11 rating). Media is electrostatically charged. This filter should be changed at least every twelve months. Certain conditions in your home will significantly add particle to the air. This will cause the filter to capture more particles than usual, shortening it's life to less than twelve months or reducing the effectiveness of the filter to capture particles. These conditions include: tobacco smoke, sanding projects, pets, woodburning fireplaces, construction work, burning candles, etc.. FEATURES: Meets the American Lung Association Health House Indoor Air Quality Guidelines No unnecessary antimicrobial chemicals added; Filtrete filtering material will not support the growth of bacteria, mold, mildew or fungi in normal use Robust frame construction enhances quality and ensures high durability at the shelf.