SummaryYou can watch a video how it works if you look in the "Thing Files" tab above (open with VLC). The holder is designed to connect cheap chinese dial gauges like this one http://www.ebay.de/itm/191381928182?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT to the extruder, to achieve a very accurate bed leveling in a short time without any electronics. After the mount is added, the dial gauge can be very easily removed and added within seconds simply by pressing/jamming it inside(no screwdriver needed), so it doesn't add much weight to the extruder while printing. The mount itself is simply screwed onto the extruder with two long M3 screws and stays there. It's very light. I've printed mine in PETG, 0.3mm layer height, 30% honeycomb infill and it works like a charm. Of course no support necessary for printing