Abstract: An air filtration media is formed of a blanket of fibers, preferably glass fibers, bonded together at their points of intersection with a binder. The blanket has a weight between about 2.5 and about 4.0 grams per square foot and the average diameter of the fibers in the blanket is within a range from 3.0 .times.10.sup.-5 to 4.1.times.10.sup.-5 inches. The blanket has an average air filtration efficiency of at least 80% and the pressure drop across the thickness of the blanket is no greater than 0.30 inches of water. The blanket can be used alone; with a permeable backing sheet; or with a second layer or blanket of filtration media, as part of a dual-phase or multi-phase air filtration media.