Steady your patio umbrella all season with a 20 inch fillable round base crafted from high-strength waterproof Hdpe. A spacious reservoir accepts sand or water for sturdy hold against gusts, while the integrated bottom handle keeps the empty 5 lb shell easy to relocate. Two adapter sleeves accommodate 1.5 and 1.9 inch poles, and a hand-turn tightening knob locks the umbrella securely so coverage stays just where you want it.