After Pack Adding LED lighting components to your TRX-4 is simple with the Traxxas waterproof power supply. This unit provides stable, regulated output with batteries ranging from NiMH to 3S LiPo. The power supply connects to the receiver and electronic speed control to provide single-point control of your lighting components. The lights turn on when the receiver is powered on. The included 3-in-1 wire harness allows the full lighting setup to be connected with a single plug.