stand for the M18 Milwaukee battery used with the multitool. It lets the tool stand upright, which is super handy and helps protect the battery from getting banged up. The file is set up so you can adjust the infill to your liking. Want it a little softer and squishier to absorb some impact? Use a lower infill. Need it rock solid? Crank the infill up. This way, it’s customizable depending on how you want to use it. Let me know what you think, and feel free to share pics if you print one!