Alion Home Waterproof Woven Sun Shade Sail - Desert Sand (16 ft 5" Triangular) Waterproof sails are made from high density polyester that blocks up to 95% of the sun's UV rays and repels up to 99% of rain water. Colorful, functional, easy to install or take down and can be used almost anywhere you want to keep the sun off. Sails come finished with a double-stitched reinforced seam and STAINLESS steel "D" rings on each corner. Needs to be installed at an angle and pulled tight so that water will run off rather than pool in the middle. 1 Year Warranty under normal usage and weather. Ideal for backyards, patios, decks, gathering areas, pools, gardens or anywhere you need a bit of shade and privacy.