This specially designed filter wrap is made to extend the service interval of K&N Filter chargers when used in dusty conditions Contains uniform micron openings like the K&N Precharger, so air can get in but dirt and other contaminants cannot Silicone treatment deflects water splashed on the air filter Uses sewn-in elastic opening to securely fasten to air filter Custom fit to each application. DRYCHARGER WR250F/450F
