K&N XStream Series Motocross Air Filters take performance to the next level with the addition of a filter within the filter's top in order to add even more filtration area for high air-flow and capacity. Each filter piece has pleated media which creates a large surface area that provides high airflow and great dirt holding capacity for extreme conditions. The two-piece design eases installation and removal on modern narrow-framed MX bikes. The epoxy-coated aluminum wire mesh, incorporated into a backfire screen, protects the filter element from harmful debris. A custom base seal ensures a precise and secure fit. K&N air filters are washable and re-usable and they come pre-oiled and ready to use! .