Amgo 24' x 24' x 24' Grey Triangle Sun Shade Sail Canopy Awning, 95% UV Blockage Water & Air Permeable, Commercial & Residential, for Patio Yard Pergola, 5 Yrs Warranty (Available for Custom Sizes)Measurement of shade sail is from D ring to D ring, edges are made slightly curved to prevent middle from sagging for best appearance and performance. Shade sail should be approx at least 0. 5 ft to 1 ft shorter than the distance between actual mounting points without any cable extension, additional installation hardware kits may be required to create mounting points and tension. Fabric material is permeable, allow water and airflow to go through to