With five layers of progressive cotton gauze media between 100% polyurethane top and base, the aFe Pro 5R "oiled" high performance filter provides excellent airflow for maximum horsepower and torque. 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 construction insures tight, no leak seal over the life of the filter. The Pro 5R air filter has a filtration efficiency of 98.6%.