Mount for VTX-Antenna for VTX transmitters with SMA/RP-SMA Pigtail like the TBS Unfify Pro. On the sides there is a mounting option for your RX antenna (which should be enclosed inside a shrink tube with a cable tie).
The Filament material for this piece may not be too soft like ninjaflex. Haven't tried it but I believe the VTX antenna wouldn't have enough support and may hit the props. So try to print with semi rigid filament. Brittle filament like PLA may not be a good idea as well ;-)