Keeps out the smallest of insects such as Sand-flies, Gnats, No-See-Ums, and also densely woven to keep pine needles from getting stuck in the roof panels of your screen enclosure. This screen adds 30% wind reduction compared to the standard 18×14 screen, but still allows decent ventilation and good visibility. This screen is a fiberglass screen with an average lifespan of 7-10 years.