Replace the screening material in your current screen-window or screen-door with PollenTEC® screening to block the entry of over 90% of ragweed pollen, over 99% of birch tree pollen, and essentially 100% of grass pollen. Winner of Window and Door Magazine's Crystal Achievement Award for "Most Innovative Window Component", this flexible, high-tech, specially coated polyester screening material filters and electrostatically traps pollen grains, allowing you to shut the air conditioner and enjoy fresh air. See these links for magnified and microscope photos of this unique material and its pollen-trapping ability, and for data from a study at a prestigious medical center. A handy homeowner or a local hardware or building supply store can install this material in your current screen frames. Compared to regular screening material, visibility is about 20% less and airflow is about 40% less.