Stitched from 900D oxford fabric with a waterproof Pu coating, this 18.5 in square umbrella base weight bag holds up to 90 lbs of sand, gravel, stones, or soil for stabilizing patio umbrellas. The detachable two-part design with fixing buckles secures around umbrella poles, while dual wide openings ease filling and emptying between seasons. Carrying handles and an empty 1 lb weight let the bag fold compactly when stowed.