Shade&Beyond Rectangle Sun Shade Sail for Patio Lawn Deck Garden Pergola (16.5'X21') High Quality Guarantee - Constructed of 185 gsm UV protected high density polyethylene (HDPE) shade fabric with strong stitched seam and durable stainless steel D-rings in each corner( The edge is curved, not straight & Hardware sells separately) Breathable Material Design - Allows cooling breezes and light to pass through for better airy and comfortable space, allows rains to pass through, so there's no pooling water( So it is not waterproof) Easy to install and maintain - Installation: Measure and clean the area where the shade sail is to be installed. Leave an allowance of 1.5-2ft between the fixing point and the shade sail to fit hardwares/ hooks or ropes. Maintenance: Clean with mild detergent or water, do not scrub it with a stiff brush, do not put it in your washing machine, clothes drier Long Use Time - 5 years warranty for fabric under normal use and weather. Please note that shade cloth is a material can shrink, usually it need tolerance for +-6 inch for each side, thank you Ideal Shade Solutions - Widely used over a patio, lawn, garden, pool, pond, deck, kailyard, courtyard, backyard, dooryard, park, carport, pergola, sandbox, driveway or other outdoor area to provide 80%-85% sunshade and protect against 95% up to 98% harmful UV rays, and make your patio privacy safe, cool and fabulous