The 15ft patio double-side umbrella provides ample shade to keep you cool and protect you from the hot sun. This umbrella made of thick steel pole and quality polyester which is anti rust and waterproof that is great for outdoor use. It is worth mention that this patio umbrella comes with a rugged base which weighs up to 220 lbs when filled with sand. The extra-large double-sided design also matches your desk and chair and provides more shade area. You can easily use the crank to open or close the umbrella which is not only laborsaving but also safe. When the umbrella is not in use you can simply close it and use provided rope to secure it closed. This umbrella comes with vents to give you more coolness and safety because it allows airflow and reduces wind pressure. Assembly is easy and can be done without the aid of tools.