Make your outdoor umbrella stable enough! Don’t worry about your umbrella swaying in the wind or falling over and hitting someone, because the 320-pound base filled with sand can support the weight of the umbrella and canopy. The sandbag base is made of high-density Oxford fabric with fine stitching, making it durable and, most importantly, waterproof.Two Oxford cloth sandbags allow for adjustability so you can customize its shape and weight. It doesn't take up space when stored when not in use. The additional black cover cloth preserves the clean appearance, giving you an elegant yet functional user experience.