Luber-finer LAF2521 Heavy Duty Air Filter Luber-finer MXM Air Filters offer 25-30 percent more dirt-holding capacity, even in the most extreme operating environments Removes 99.9 percent of airborne contaminants MicroGold fiber technology provides an average of 50 percent more dust-holding capacity More pleats result in longer filter life, maximum fuel efficiency, and significantly improved fuel consumption Offers high quality filtration when experiencing harsh environments, dusty or dirty roads, or frequent idling time