American Air Filter 20" X 30" X 1" Strata Density Fiberglass Air Filters Sold in packs of 12 Protects HVAC coils from dirt for general air filtration applications with light to medium dust Constructed with a strong, chipboard frame bonded to AAF manufactured premium grade fiberglass media Coated with a light adhesive to increase the amount of dirt the filters can hold The chipboard filter frame, free of sharp edges Priced and sold by the case of 12