Prevent sand, mud, and dirt from damaging the air filter in your 2003-2007 Ford 6.0L Powerstroke with a Pre-Filter. Pre-filters are manufactured from a breathable material that lets air through while blocking large debris and contaminants. 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. Purchase pre-filters from AFE, K&N Engineering, S&B, and many others at XDP! You can get the right pre-filter for your intake by matching up the filter dimensions or from the corresponding filter part number.