Putting together a high power rocket is actually easier than you might imagine. In this fourth video, you'll see how install rail buttons and the Aeropack engine retainer. We're trying something different in this series of videos. I'm personally going to move from being in front of the camera, to being behind it. The construction of the rocket is being done by Erin Card, who works here at Apogee Components as web designer and customer service representative. Since we're video recording the process of making this kit, we're taking a bit longer than normal. But that's cool. Every time you get to see Erin, she's wearing something different.