This is a box that allows you to quickly insert and remove the NXT 2 brick from your MOC. This is a side-product of a MOC that I am making. For my MOC it needs modification to the point that it is hardly recognizable as a box. So, I decided to share this as a stand-alone. For your MOC, it probably also needs modification, but now at least you have a design for the hook that keeps the brick in place. I have not tested it in a real MOC with the cables attached, but I don’t see why it wouldn’t work. Obviously, the cables need some slack to allow you to take out the brick.
You can download the design in Ldraw here. I made it on a Mac with Bricksmith, but the file should work with other Ldraw software for Lego designs.