The Skyspan 18 foot Hexagon Cantilever Umbrella has a mast and cantilever arm made of powder coated galvanized structural grade steel. Arms are structural grade aluminium. Features a retractable winding mechanism allowing for the arms to collapse in extreme weather. The umbrella canopy is made from a PVC Coated polyester fabric which is both 100% waterproof and UV proof. The retractable umbrella range has been wind rated by engineers withstanding 75mph when opened and 93 mph when retracted. After many years of engineering and endurance testing, SkySpan offers an umbrella that will surpass all expectations.