The aFe filter restore kit comes with a squeeze bottle of aFe blue filter oil and a spray bottle of aFe filter cleaner. aFe filter oil is highly refined and helps capture the smallest debris. aFe's advanced formula will not harm MAF sensors or cause check engine light warnings. Works great paired with aFe filters or to upgrade other oiled filters. aFe's cleaner is specifically formulated to release dirt without harming the microfibers critical to efficient filtration and airflow. Recommended re-oiling every 20-30k miles. Please do not over oil the filter.