DJI RS Intelligent Tracking Module, Compatibility: DJI RS 4 Mini, RS 4, RS 4 Pro

Press the bottom latch to directly attach it to the DJI RS 4 Mini via magnetic connection. When used with an adapter bracket, it can be mounted on the DJI RS 4 Pro or DJI RS 4. Compatible Products DJI RS 4 Mini.

eBay