Luber-finer AF4000 Heavy Duty Air Filter Luber-finer air filters remove more than 99 percent of airborne contaminants Provides 25-30 percent more dirt-holding capacity, even in the most extreme operating environments High efficiency filter media technology captures harmful particles that can damage your engine Offers high quality filtration when experiencing harsh environments, dusty or dirty roads, or frequent idling time Meets or exceeds requirements for all new vehicle warranties