Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2073642.

This is a control plate that goes underneath the pack at the bottom. The purpose is to mount a switch for power to the pack, a switch for power to a smoke kit, an XLR 4 pin charging port for the battery, and/or a "blue brick" 1/4 inch charging port. I have also used the holes for a 1/4 socket to connect an mp3 player. Paint it metallic silver. If you print, please post a pic!