Build your own models powered by air and water pressure to learn about the laws of physics. This unique kit allows you to build two different air and water-powered systems: water-jet propelled cars and hydro-pneumo (which simply means air pressure and water pressure) powered engines. The hydro-pneumo system uses a self-contained air and water turbine system as a motor. Construct 15 models including a truck, excavator, radar car, tank, antique car, helicopter, motorbike, backhoe, rocket car, forklift, roadster, propeller plane, grinder, and cuttering machine.