Hello, this is a Robot chassis design to mount VEX parts on. I use this in my classroom for students to learn the basics of RobotC. You can mount motors, servos, and sensors on it so that students can navigate through a maze or follow a line. Works with VEX bolts, axles and other accessories. Also available to print is a VEX battery holder that mounts on the back the of the chassis. Once again, the slots are spaced in a manner that supports VEX screws. The battery should fit snugly (press fit) inside the holder.

Check out the video here: https://youtu.be/-a6rHuMV3GQ