Prusa i3 tool holders based on http://www.thingiverse.com/thing:145780 Just added the plier space and the calliper piece for the other side Calliper piece is also already included with support inside. The calliper is holding good for me also during printing, but keep in mind that its quit heavy, and if you work on or move around your printer you should remove it before, or its glass might get broken like mine :)