Three Birds Casual 18-Inch Round Umbrella Base Non-toxic 100-percent recyclable material Resistant to rain, salt water and chlorine Overall dimensions: 18-inch by 18-inch Non-toxic 100-percent recyclable material Resistant to rain, salt water and chlorine Overall dimensions: 18-inch by 18-inch Includes a hardware pack with tools and instructions for assembly No maintenance required, easily clean with soap and water