Our Natural Cork Massage Ball Trio contains three smooth and firm cork massage balls. Powerful self-healing tools, massage balls enhance joint movement, relieve tension, increase circulation and calm your nervous system. Lean into a wall, chair or the floor to create just the right pressure. Experiment with the two unique sizes (1 small + 2 medium) to find the exact pressure you're looking for or roll the matching massage balls on either side of your spine for balanced release.