The Heavy Duty 30-Litre Fillable Water/Sand Base for Flags, Umbrellas, and Garden Poles is a round-shaped, black plastic base designed for outdoor use in gardens and on patios. Its fillable feature allows for easy customization with water or sand to provide stability for flags, umbrellas, and garden poles. In good condition. 20 inches across and the inner hole diameter is 2 inches. Check out my other items too.