Each cube book has 6 'pages' on one side, then turn them inside out to find another 6 'pages'. An innovative fact filled reference to the human body covering all the major body systems - heart, lungs, water works, digestion, ear, eye, bones, muscles, blood, nerves and the brain. Did you know that it takes 40 muscles to frown, but only 15 to smile? Irresistibly tactile - turn to learn!