Windscreen4less 12ftx12ft Sun Shade Sail UV Block Fabric Canopy in Green Square for Patio Garden Customized 3 Year Warranty, x 12 Made of 100% brand new high-density permeable 180GSM polyethylene knitted fabric material. Sun shade sails have curved sides to enhance pull strength and prevent drooping. (Middle-center of the sun shade will be shorter in width due to curves). Sail comes finished with strong stitched seam, fitted stainless steel D ring on each side. Sun shade can be used over a patio, driveway, lawn, garden, pool, deck, courtyard, dooryard, park, and carport Allows cooling breezes to pass through to increase the sail's cooling power, shades are non-waterproof.