Anatomy and polymers science kit! Great Halloween activity or Halloween party decor This teeny detailed brain is made of a polymer that expands. Just add water and see your brain grow. This science kit starts out as a great looking detailed tiny brain anatomy model. When placed in water over the course of days it demonstrates the super water absorbing properties of polymers as it becomes a big brain. All in a cool 5.25x2.5x2.5" box POS display holds 12 units Fun activity for homeschool, back to school. Perfect for birthday gift bags, stocking stuffers or any time you need a little STEM.