Make rubber balls, foam rubber, erasers, rubber stamps, water proof cloth and rubber dinosaurs. Learn about an amazing and useful natural substance, states of matter, and chemical reactions. Note: Contains latex. Not recommended for persons with allergies to latex or proteins.The REGULAR KITS (singles) include enough materials for repeating each experiment 2 TO 3 times. The larger CLASSROOM KITS contain 5 times the materials of the single kits, enough for a 5 STATION CLASSROOM SETUP that can be REPEATED APPROXIMATELY 3 TIMES.