When using a wireless battery pack, you can plug this into the USB C port on the controller to block the bright LED light when playing in the dark. On my controller, I still get a very dim halo showing under the controller's plastic so I can still see if the LED is solid or flashing. It wasn't even bright enough to pick up on camera, perfect for a dark room.
The author remixed this model.
Used this USB C plug to design a light blocker for the Xbox Series X/S Wireless controller.