This is a battery holder for the Rev Robotics 12V slim battery!
This slim, yet protective case was designed with frequent battery changes in mind. Designed to mount to REV 15mm extrusion, but could probably attach to any build system.
If you want your team's number on the side, download the .f3d file, load it up in fusion 360, and edit the text in sketch 11 to whatever you desire.
If this helps out your team, please send team 9421 some love and post a make!