http://www.ApogeeRockets.com - If you have a cluster motor rocket, and you don't want to fly all the motors at the same time, you can create a simple ejection plug. What this does it to effectively seals off the empty motor tube so the other ejection charges (from the other motors in the cluster) don't accidentally go out the rear end of the rocket. They are made from a simple tube coupler and a cardboard disk that is glued on top. Add a string loop, and it is easy to push it in and pull it out. The rocket kit shown in this video is called the LOC Ultimate. See a promotional video and a launch at: https://www.youtube.com/embed/wyxIzv1G6z0