Double Lock Design: Featured with 2 adjustable knobs for securing umbrella to base, to ensure optimal strength and stability no matter the umbrella's pole size Various Umbrella Available: Versatile base features a steel pipe that accommodates all market umbrellas, ideal for holding most 6-10ft umbrellas with 1.5" (38mm) to 1.9"(48mm) pole diameters Water or Sand Filling: Base can be weighed down with up to 55 pounds of sand or 19 liters of water, or empty it out for a lightweight stand that can be taken anywhere Rustproof and Anti-corrosion: Made of durable HDPE material, all weather resistant. The steel pipe is galvanized and would not be corroded easily, which has good solidity and would not let the umbrella tilt easily Easy Storage: Simply remove the steel tube for a slim design, easily store the base in compact space year-round.