Modeled after the Bulletpoint Mounting Solution's universal 20mm ball mount, I wanted to be able to mount other items to the arms. I modeled and printed two versions, the first is a pretty close copy of the metal one and the second is a just a taller version at 56mm tall (original is 36mm), with a thicker center portion at 12.5mm (original one is 10mm) for increased strength. My intention was to attach an 8 switch controller to a spare mounting arm that is attached to the dash of my Jeep. The models do not have holes in the bases as the intent was for them to be glued to attached with double-sided 3M tape. I have confirmed that both fit in the mount arms perfectly. I printed these with 70% infill and 0.2mm layer height for increased strength but depending on how heavy an item you want to mount, you may need more or less infill. The original mount is the one to the far right, the ones I designed are the two on the left.