HPS Performance Drop-In Air Filters are direct replacements for your vehicle's engine air filters. HPS uses a low pressure injection molding process to produce the panel filters' frames, ensuring high quality products that allow for up to 25% more airflow than the leading brand. The woven cotton filtration media is encased between durable stainless steel mesh to retain their rigid pleats. These filters are coated with a specially formulated synthetic oil that traps fine particles within the double-layered woven cotton media. They install in just minutes using little to no tools, depending on the vehicle. HPS Performance Drop-In Air Filters should be serviced every 30,000 miles using the HPS Performance Air Filter Cleaning Kit to maintain optimal filtration and airflow. Manufactured using only high-quality materials, these HPS Performance Drop-In Air Filters are engineered to last and are covered under HPS's 10-year limited lifetime warranty.