True Blue 10x10x1" Fiberglass MERV Rating 2, 30-Day Filter. This filter effectively traps pollen and dust/lint, reducing dust and dirt buildup in air ducts, air conditioners, and furnaces. Made from heavy chipboard in a one-piece design, it features continuous filament spun glass filtering media that functions without a retainer. The resinous bonding agent provides rigidity and resistance to media compression. With a low initial pressure drop, it helps protect HVAC equipment and reduces energy costs.