The high durability UV resistant polyester fabric of the double-sided outdoor umbrella is waterproof,fade-resistant, rust-proof, and blocks most harmful UV rays, and have better color fastness performance. And cleaning is easy – just wash it with mild soap and water. The wind vent cools air under the twin umbrella, which allows the air to flow better and prevent inversion. Reducing the wind pressure and maintains the balance and stability of the garden large umbrella