Push the straw into the base of the balloon ball and then blow into the other end to inflate it. Once inflated to the desired size, remove the straw and the balloon ball will stay at that size. Throw it, bounce it and squish the air-filled balloon and it will retain its size and shape. Reinsert the straw and the air will leave the balloon again, deflating it ready for next time. Available in an assortment of colours.