Replace the old air filter in your 2011-2016 Chevy/GMC 6.6L LML Duramax with a Drop-In Air Filter. Shop for drop-in air-filters from manufacturers like S&B Filters, AFE, K&N Engineering, and others available at XDP. Direct-replacement drop-in filters are manufactured with a paper filter media, and aftermarket filters are made with an oiled cotton-gauze, or synthetic dry filter media. Air Filters provide your engine with clean air by trapping harmful contaminants such as dust and debris before entering the intake. Drop-in air filters are aptly named as they have a "drop-in" installation that allows them to fit inside of your factory air box.