In order to get really low DO (dissolved oxygen) in your beer cans, it's important to fill the can right to the top to the point where it's slightly overflowing.  This inevitably means some drips on the side of the can will flick off sideways when you turn the machine on.

This splash guard prevents these annoying splashes making a mess in your brewery area.

Also fantastic for tight spaces or congested bars where growler filling is done right next to other staff and equipment that you do not want to get splashes on.