Progressively finer mesh cotton gauze/synthetic media between 100 percent polyurethane top and base;this high flow oiled performance filter provide maximum protection with highest cumulative filtration efficiency for severe duty environments. Outside expanded metal protects as well as enhances the look of the filter. Washable and reusable for multiple cleanings; the tall open evenly spaced pleats provide excellent dust holding capacity for longer service cycle between cleanings. Pliable polyurethane with integrated bumps insures tight no leak seal over the life of the filter.