Home > Shop Duststop Products DUSTSTOP 16x25-1" FURNACE FILTER 3pk Item #: 27157935 $5.10 ea. Add to Cart DUSTSTOP 20x20-1" FURNACE FILTER 3pk Item #: 27159840 $5.10 ea. Add to Cart DUSTSTOP 20x25-1" FURNACE FILTER 3pk Item #: 27161745 $5.10 ea. Add to Cart