This plug fits in basic FRC Anderson cables, and is extremely useful to indicate the charge state of the battery. Note: you may need to scale this up 9 times the original size if it is too small. I have made a model that allows you to put your team's name and number on this here: http://www.thingiverse.com/thing:624106 Thank you!! -Team 4293You can build this on almost any standard 3d printer. In my personal experience, i have found that using abs plastic is the best option. If the model appears to small, you may need to scale the model up by 9x.