主权项 |
1. A ball having an outer shell, an interior, and a radius, comprising:
an opening forming a portion of the outer shell that provides access to the interior, at least one exercise weight cavity in the interior configured to receive one or more exercise weights, a filling material disposed in the interior, between the at least one exercise weight cavity and the outer shell, and one or more balance weights that are different from the exercise weights fixedly disposed within the filling material. |