Heavy, works excellent
Works great on our half umbrella. It saved it from going over our 4th floor balcony when I forgot to close it and it became weighed down with ice/snow. It toppled right over the side, but stopped due to the heavy base. A lighter base would have let it go over and crash down to the ground. Also works great for sudden winds.
It also has added hardware that allows you to anchor the umbrella to the floor through the bottom of the base.
Just be sure to leave some room for ice expansion if it will freeze in winter.