Flanders Permaire Media Rolls Service Roll, Up to MERV 4, 30 in. W x 30 ft. H x 1 in. DDurable synthetic, self supporting media roll Innovative replacement media offers longer service life and better structural integrity with no frame required Replaces any size furnace filter Up to MERV 4 rating: Efficient removal of Dust, Lint, and Pollen Washable and reusable Easy to cut to size Available in , 1, and 2 media thickness Lasts up to 30 days Permaire Media Rolls are naturally rigid. Once cut to the proper dimensions, they are complete