If you own a Behringer X-touch DAW controller and a Behringer X-touch extender the standard side panels create an unnecessary large gap between the two units when placing them side by side. Removing the sidepanels entirely, leaves a nasty hole / gap in the front of the steel casing. That is where these sidepanels come in.

chang screws to M4x10 Socket Countersunk Screws

These sidepanels can be used for: placing an X-touch next to an X-touch extender (as stated above)