Easy Mobility - Patio Umbrella Base with 4 universal wheels can be moved easily to any place you like Universal Fit - Features 2 adjustable knobs to fit 6 to 15 ft center-pole umbrellas with 1 1/4' to 1 7/8' pole diameter 2 Weighted Methods - Fillable design allows you to increase its weight by adding water or sand Durable Material - Made of durable plastic which is not easy to break and deform, and does not appear to rust Easy DIY Installation - Quick & simple assembly with all accessories included