Large base with 150lbs capacity is free to add wet sand to boost stability well with 1.5" 1.9" firm poles and 7.5ft 11ft patio umbrella built-in drain hole, and the large capacity makes it a perfect flower box -in a snap. Tighten the umbrella pole into the base Powder coated steel base which is rust resistant and stable with 2 wheels for effortless movement Convenient design is ideal for various detailed instruction manual You will get a stable quickly