CHOKING HAZARD — Small Parts. Not for children under 3 yrs. Hours of fun in an educational toy! Simply put baking powder (not included) inside the plastic submarine, close it up and submerge them into water. The reaction of the baking powder and water will cause the subs to dive and surface as they releases carbon dioxide bubbles. Fun for home and in science class. Case includes 24 – 2-ct. packs of Bubble Action Plastic Diving Submarines assorted among the 2 color combinations shown. Ages 4+.