aFe MagnumFLOW Air Filters 3-1/2F x 6B x 4-1/2T (INV) x 6HConstructed with 100 percent polyurethane on top and bottom, this high flow, oiled performance filter is our highest flowing media for improved horsepower and torque. Five layers of progressively finer mesh cotton gauze media provide maximum airflow for best performance results. Washable and reusable for multiple cleaning cycles, the tall open evenly spaced pleats provide excellent dust holding capacity for longer service cycle between cleanings.