The DJI R Multi-Camera Control Cable (Mini-USB) connects a camera with a Mini-USB port to the Camera Control Port of DJI RS 2/DJI RSC 2 for camera control.
It also lets you connect the DJI Ronin Focus Motor to the gimbals for a power and communication connection. Please visit the DJI website for the current list of supported camera models and functions. The cable is 30cm in length.