Our Polly Series 20x20x4 high efficiency filters are available in four different filtering efficiencies - MERV 8, 11, and 13. They're constructed of 100% synthetic fibers that are electrostatically charged to capture dust particles as small as a microscopic 0.3 microns, sending cleaner air through your system and home.
We can even include a length of foam gasketing with your order. Once inserted around the perimeter of the filter housing, it will help eliminate any air by-pass around the sides of the filter frame. You can order the Gasket set below.