4 years & up. Explore 8 organs in your body with these fun sensory vests. Push and move the liquid to see how the hearts pumps blood through your body, push the lungs to get oxygen to the blood, churn the stomach to investigate how food is digested. Includes the heart, lungs, kidneys, bladder, circulatory system, digestive system, ureter, stomach, liver, pancreas, large intestine, and small intestine. Includes 2 vests measuring 9.5"W x 23.5"L.