With three layers of progressively finer mesh synthetic media between 100% polyurethane top and base, the aFe Pro Dry S heavy duty cylindrical performance filter uses no oil for maximum convenience. 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. The Pro Dry S air filter has a filtration efficiency of 99.2%.