This is a TPU Axii holder for the realacc antenna

https://www.banggood.com/Realacc-UXII-Stubby-RHCP-U_FLIPEX-IPX-5_8GHz-1_6dBi-Super-Mini-Antenna-For-TX-RX-Fatshark-Goggles-R-p-1256043.html?rmmds=myorder&cur_warehouse=CN