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 filtersBanks 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 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.