Highly recommended in dirty environments. Keep your Ram - Air Filter protected from large debris, bugs, mud, etc... Built from a breathable material, the Banks Pre - Filter goes over your air filter, provides additional protection, and can even extend cleaning intervals. Works with both Dry and Oiled filters. Banks pre - filter wraps are designed to work with your Ram - Air intake system and are constructed from a polyester mesh with uniform micron openings. It improves the filtering of larger debris and dirt by preventing them from getting embedded into the filter. This allows your your Banks Ram - Air to breathe easier for longer by increasing the time between services. Its hydrophobic surface has been treated to repel water and improve performance in humid or wet environments. The pre - filter is able to resist heat up to 400 degrees Fahrenheit and will not shatter in freezing temperatures.