The BW30 is an optional cast iron 30 lb. weight that can be added onto the Treasure Garden Art Deco, Classic, and Monaco bases for additional weight. Recommended for use with free-standing umbrella applications. It is very important to check the umbrella base weight requirement for your umbrella. Before assembly, decide on the location of the umbrella. Allow ample height to avoid damage to your umbrella during assembly and usage. Choose a location that is level and sturdy. Avoid any sloping or soft ground.