Balance on it, Sit on it, Stand on it, Kneel on it – the choice is yours - Ideal tool for improving balance and posture. Helps tone trunk and abdominal muscles without strain. Can be inflated or deflated to obtain the desired firmness. Available in two colour coded sizes: Yellow 30cm and Blue 40cm. Made from DINP (diisodecy phthalate) as opposed to the toxic DOP(di-2-ethyl hexyl phthalate) plasticisers. Latex free.