This is for spool mount. You need this part to avoid filament bend problems when printing at high Z heights.I have used the parts from http://www.thingiverse.com/thing:30742, but there is problem with my improved Prusa Mendel with new frame vertex. Because i can print at higher Z height, the spool holder part blocks the filament at x-min and x-max side.Thus i designed a new part to keep the problems low. The filament bend now much less and there should no serious problems when printing at high Z height.The part is thick enough to hold the heavy filament spools. Designed and build with Google Sketchup.