Water Rockets are perfect for low-cost rocket flying! Uses air and water as rocket fuel. There's no-cost per launch - You can fly them over and over - and You control the flight performance by varying amount of water and pressure. Flies to over 200 feet! Water Rockets are engineered to amaze students, youth groups, and camps. They are a great STEM learning tool that allows students to explore the “What If I…” process of discovery, exploratory learning and problem solving. You will need twelve 24 oz, 1 liter, or 2 liter PET soda bottles (not included). Included in this Classroom Pack are the supplies you'll need to build 12 complete water rockets (except you supply the PET soda bottles). Launch System not included - if you don't have our Water Rocket Launch System, you need to order it also - see Q7308 Complete Water Rocket Launch System. You'll also need a standard bicycle pump with a pressure gauge. Our unique Rigid Foam Fin system requires a 'Low-Temp' Hot Melt glue gun. Students assemble the pre-cut and slotted fins, then apply the Hot Melt glue to the outside of each fin joint - this assures a perfect fin alignment every time! Includes: 12 pre-cut Rigid Foam fin sets 12 translucent molded nozzles 12 Foam Recovery bumpers Color assembly and use instructions