Prevent sand, mud, and dirt from damaging the air filter in your 2011-2016 Chevy/GMC 6.6L LML Duramax with a Pre-Filter. Purchase pre-filters from AFE, K&N Engineering, S&B, and many others at XDP! Each pre-filter is manufactured from a breathable free-flowing material that will block contaminants and debris while allowing proper airflow to the engine. Pre-Filters are installed over top of your air filter and serve as another layer of protection from airborne contaminates that could otherwise damage your filter, air intake, or engine. Get the right pre-filter for your intake by matching up the filter dimensions, or by using the filter part number.