With seven layers of progressively finer mesh cotton gauze and synthetic media between 100 polyurethane top and base, the aFe Pro GUARD7 heavy duty cylindrical performance filter provides excellent protection. It's the media we recommend for the most severe service conditions, these filters have an efficiency of 99.7. 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 flange with integrated bumps insures tight, no leak seal over the life of the filter.