Get ready for some fun. This little rocket has heaps of power. Make sure you follow the safety instructions and put on your glasses/goggles!
You need to get yourself some bicarbonate of soda (bicarb) and some white vinegar. Without going into the science (Why bicarb reacts with vinegar), the reaction causes gas expansion, which pressurises the inside of the rocket. Then, once the pressure has a greater force than the friction holding the rocket to the launch pad, it takes off. Pushing the liquid and gas out of the bottom of the rocket, and propelling the rocket up via thrust.
And when we say propel, we mean PROPEL! This little tiny rocket, with a little tiny bit of bicarb and vinegar, will get to about 5 metres in the air. Kids love it!