The Gonge Air Board Set and Giant Air Board are balancing boards with a soft inflatable base. Using the Gonge Air Board Set and Giant Air Board you can Sit, rock and step on. Exercise control and strengthen muscles in the ankles and legs. Diameter of the Gonge Air Board Set and Giant Air Board: Giant 58cm, Set of 3, 39cm.The hard surface offers a safe grip for the feet while the inflatable base ensures smooth and gentle movements.Gonge Air Board Set and Giant Air Boards may be adapted to the functional level of the user by adjusting the pressure of the inflated air, increasing the pressure will speed up movements and make the balancing board more challenging.