A Cartesian diver is a classic experiment that explores the properties of air. Squidy kits promote hands-on learning and stimulate scientific inquiry. Squeeze the plastic soda bottle and watch the squid-like creature sink and swim in the water. Super Diver Kits promote hands-on learning and stimulate scientific inquiry. Contains enough materials to make thirty Cartesian divers. Make Cartesian sinkers, retrievers, helicopters, sealed divers, and many more. Includes Steve Spangler1s Soda Bottle Science book. Counting is a kit of five divers which ascend and descend in numerical order. The kit includes a special pump.