Durable Large PE Fabric 18x18Ft Square Desert Sand Outdoor Sun Shade Sail Canopy UV Protect Portable for Sunscreen Shelter Patio Pool Spa Beach Campground Picnic 18' Square Shade Sail, tension mounted steel D-rings double stitched into the corners. Please note all sail shade edges do curve inwards for aesthetics and durability. 4' of weather-resistant polypropylene rope for each corner, 4 Carabiner, and carrying case. (sail shade is measured from D ring to D ring)