Double Lock Design: This outdoor umbrella base features 2 adjustable knobs for securing the umbrella to the base, ensuring optimal strength and stability regardless of the umbrella's pole size Holds Various Umbrella Sizes: The versatile base features a steel pipe that accommodates all market umbrellas, making it ideal for holding most 6-10 ft umbrellas with pole diameters ranging from 1.5 " (38 mm) to 1.9 " (50 mm) Water or Sand Filling: This umbrella stand outdoor base can be weighed down with up to 55 pounds of sand or 20 liters of water, or emptied for a lightweight stand that can be taken anywhere Product Details: The heavy-duty umbrella base is made of sturdy HDPE material and features a weather-resistant steel tube for excellent sturdiness. The size of the base is 19 inches x 19 inches x 4.3 inches, with a maximum loading weight of 50 lbs. It is not suitable for offset or cantilever umbrellas Applicable Scenarios: This round umbrella base is designed with line style, elegant and classic, suitable for home, garden, resort, swimming pool, company rest area and various residential or commercial uses. Your best choice for recreational shade The round base design of this product is big enough to hold the umbrella and features two hand-turn tightening knobs for securing the umbrella to the base. It has a double-lock design with one hole inside and one knob outside, ensuring a tight fit for your umbrella. Plastic inserts on top of the steel pipe are compatible with Φ1.5" (38mm) or Φ1.9" (50mm) umbrella poles. This umbrella base features a sleek black line-style design, which is elegant and classic. It is suitable for different decor styles; you can place it on a balcony, in a yard, or beside a swimming pool. It makes for a perfect companion to your umbrella.