The repeater module expands the signal of the wireless module and improves the transfer quality over great distance or even through thicker walls.
It can be plugged vertically or horizontally in a socket.

The audio module can be connected to a stereo system and streams the music files, which are saved on the hard drive module, over the stereo speaker.

The media module can be connected to a display device (like a TV).
It enables the user to view pictures, videos and music files saved on
the hard drive module.