Intended to keep my breaker bars from rolling around and also just to help add some organization for my toolbox. As with most of my toolbox organization stuff, I printed mine from TPU. The diamond pattern on the top and bottom surfaces was intended to 1) keep the TPU from destroying my build plate, and 2) I was originally going to use this diamond pattern to make things stackable/modular, but haven't gotten around to building it out any further.