The used DJI Ronin 2 Power Hub connects to the pogo-pin interface on the Ronin 2 and provides four ports for accessories, data, and camera control.
Three ports allow you to power accessories at 14.4V as well as transmit data, and an RSS port lets you connect a compatible camera and trigger record start/stop using the Ronin 2 remote controller or mobile app. Optional proprietary control cables are required for connecting the camera. The four ports are provided in a rear-facing position to prevent cable connectors from interfering with other accessories.