The new B74 is the pinnacle of what 4wd RC buggies can be, however some small details were left un accounted for. Mainly, there is no safe and clean way to run the battery wires from the ESC to the battery without running the risk of them hitting the uncovered spur gear. Enter the VSR wiring harness, which holds your battery wires in place and avoids any risk with the spur gear. It mounts on the carbon top plate on top of the center diff or slipper. Note, you will have to un-solder your bullet plugs in order to feed the wires through the harness.