San Diego Sail Shades 15' Square - Sandy Beach Constructed of Heavy Duty (185GSM) polyethylene fabric. Shade sails are remarkably strong with amazing longevity to remain installed in hot/dry climates as well as cold and damp. Available in a wide range of colors and sizes. Optimum Ventilation: The unique fabric design allows cool air to penetrate the shade sail providing an airy, comfortable, and well-ventilated space. Ultra-Violet Protection: US Shade Sails has a UV protection rating of 89-93% and shade protection. The amount of protection greatly reduces the exposure of UV rays which can lead to skin cancer. Free Air Conditioning: US Shade Sails will lower the ambient air temperature reducing your properties cooling cost and energy consumption. The savings will pay for the Shade Sail's over time, with the right design. Includes: 15' SANDY BEACH Square Shade Sail, tension mounted steel D-rings double stitched into the corners, 4 of weather-resistant polypropelene rope for each corner, and carrying case. **(Please note all sail shade edges do curve inwards for aesthetics and durability and are measured from D ring, to D ring.)**