Build your own models powered by air pressure and water to learn about the laws of physics. A larger, super-charged version of our original Air+Water Power kit, this kit allows you to build more powerful models using two different air-and-water-powered systems: water-jet propelled cars and hydro-pneumo (water-air) powered engines. The hydropneumo system in this kit uses a larger, more powerful self-contained air-and-water turbine system as a motor. Two pressurized air-water tanks are included, allowing you to build two water-jet propelled cars simultaneously and race them against each other. Construct 30 models including pressurized water guns, air-and-water turbine driven cars, rocket cars, and jet boats. The water-jet propelled cars are a fun outdoor activity, while the self-contained hydro-pneumo powered models are fun both indoors and out. Compete with your friends to see whose water-jet propelled car goes the fastest, and whose hydro-pneumo car goes the farthest! 60-page color instruction book. 176 building pieces.