15FT Large Patio Umbrella with Base The 15 ft x 9 ft patio umbrella provides a larger shade area when fully opened, with up to 133 sq. Ft. Of shaded area. The pool umbrella will come with a durable base that includes a cross base, two sandbags and a polyester cover. (Note: Sand is not included, each sand bag holds 100 lbs of sand to keep the umbrella stable) Premium Quality Polyester GDPFN double sided outdoor umbrella is made of 100% polyester fiber, 220g/m thickened fabric with excellent fade resistance. And the surface uses PA coating, which is waterproof and also blocks the sunlight better, blocking 99.9% of UV rays.