The HeroStrength® “Nimbus” Ring is designed to store your stability gym balls in the most simple and compact option. This halo-shaped “Nimbus” ring will allow you to organize and stack inflated gym balls; one on top of the other and prevent them from rolling away. Purchase additional rings to stack additional HeroStrength® Stability Balls for a Club Pack up to THREE inflated balls without the need for any bulky racking system.