The Dirt Demon Ultra Shield is offers the most efficient and cost-effective solution for providing a cleaner household. Made with AAF's patented, self-supported media, Ultra Shield pleated filters are 50 times more effective than fiberglass air filters. New technology eliminates the need for metal reinforcement, allowing for an effective filter with greater handling safety. Electrostatic media attracts microscopic airborne particles like a magnet, providing cleaner healthier indoor air. The Dust Shield lasts for up to 90 days.