These lifelike 1- and 5-pound fat and muscle models provide a hands-on demonstration of the difference between body fat and muscle and the importance of physical activity. Globs of Fat™ are made of BIOLIKE 2™ synthetic tissue and have a realistic, squishy feel. Firm lean Masses of Muscle™ models are rigid and streamlined, just like real muscle tissue. A great addition to any lesson on good nutrition or physical activity.