Keep your filter safe from sand, mud, and other debris when you purchase a Pre-Filter to your cold air intake on your 1994-1997 Ford 7.3L Powerstroke. Finding the right pre-filter for your intake can be done by matching up filter dimensions or by using the corresponding filter part number. Pre-filters feature a breathable construction with a free-flowing material that allow your filter to breathe while blocking out large debris and contaminants. Purchase pre-filters from AFE, K&N Engineering, S&B, and many others at XDP! A pre-filter is installed over your air filter and helps to extend cleaning intervals while also blocking out large debris that might otherwise damage your air filter.