They effectively reduce heat on your patio, backyard, and other outdoor areas because they provide excellent protection from the sun and its harmful UV radiation. Constructed with woven high-quality and high-density polyethylene weave fabric (185 gsm), the sunshade blocks more than 95% of harmful UV rays. The weave fabric material is color-fast and won't rot, mildew or mold. Beat the heat with this must-have summer item which lowers the temperature beneath it by up to 6.5 degrees.