Sturdy 4 square plate construction supports your offset patio umbrella stand stably-Made of high density HDPE material, sun-proof, waterproof and durable-Filled with sand or water to add additional weight to improve stability in windy conditions-Applicable to 9 ft and 10 ft offset patio umbrella-4 solid metal connecting hooks can firmly connect the board into a whole-Easy-to-fill spout makes for convenient filling, cleaning, and storage-Portable handle of each plate for convenient carrying-Firml