aFe's air filter restore kits use highly refined oil, which is proven less likely to foul MAF sensors than other oil. They work great with aFe filters and are a great way to upgrade competitive oiled filters. aFe's cleaners are specially formulated to release dirt without harming the microfibers critical to efficient filtration. aFe air filter restore kits have a simple 3-step restoration procedure, which restores your filters to "as new" condition. These kits are available in a variety of colors and sizes.