Four HDPE plates form a cantilever or offset patio umbrella base that helps stabilize the umbrella by spreading weight across separate sections. Each plate has its own spout so you can fill or drain sand or water without moving the whole base, reaching up to 240 lbs with sand or 21.2 gallons with water. The combined base supports up to 200 lbs when filled. Hidden handles make the 22-lb set easier to carry, and the stackable design saves storage space when not in use.