It's made for the USB RS-485 converter with FT232RL + SN75176. The XLR plugs are from AliExpress. I simply glued the module into the case, and the XLR plug is secured with 2mm screws. The lid is also secured with 2mm screws.
Links:
converter: https://www.gme.cz/v/1507873/modul-prevodniku-usb-rs-485
The author marked this model as their own original creation.