This is part 3 of 3 of my review of the Estes Tandem-X launch set. In this part, I do a complete build of the Crossfire ISX with tips along the way for this Skill Level 1 rocket. It can be launched on A,B,and C engines. At the end of the video, I launch it on an A8-3 and also a B6-4. Great flights both times.