The Gyro Chaser is a highly efficient model rocket that uses the common 18mm diameter rocket engines (A, B and C-size). It launches as a rocket, and descends to the ground as a helicopter. What makes it fun and unique is that it carries the rotor blades internally, inside the body tube of the rocket. So spectators don't know that it will come down different from a normal model rocket. They will be thrilled when the rotor blades spring open and it begins to spin rapidly. But watch out, and have your running shoes on; because it goes so high and hangs in the air so long, you'll be running a long way to chase this rocket. That's the downside of having a rocket that is so efficient. This rocket kit requires assembly. While it is a challenging model to build because it has many small parts, the instructions are in video format so you'll be walked through the assembly in a step-by-step fashion. You'll have it built quickly, and you'll be impressed that you can build such a unique rocket yourself. To fly this rocket, you'll need rocket engines and a launch pad set.