This is an universal holder for a DJI Mic 1 transmitter. It can be used to mount the mic to a rod or a handle. The top part is fixed to the bottom part using an M3 screw. You need a threaded insert in the bottom part for the screw (alternatively, you could also screw into the plastic). 

The bottom part will probably be customized to your use. The included one is a cylindrical insert with 16mm diameter, fitting on a standard handle bar, but all you need is something to screw in the M3 screw from the top.