Each coated plastic card features an active photograph of a child or adult. When placed on a light table or in front of a light source, an image appearsfeaturing one of the body's important systems: skeletal, muscular, nervous, endocrine, respiratory, immune, digestive and urinary. Includes: 16 doublesidedphoto cards, 8½ x 11" (22 x 28 cm) and idea guide.