Volant Universal Round Black Prefilter (Fits Filter No. 5114/ 5115)VOLANT PRE FILTERS are factory treated using a proprietary hydrophobic process and are manufactured from the same durable polyester material as their race proven regular style. This unique material contains uniform micron openings that will filter out debris . 005 or larger. This pre filter will prevent splashes of water, mud and sand from saturating your air filter.