Experimenting with ninjaflex i found that i could not print with the springy filament without it buckling inside of the extruder housing and making a mess. This part simply provides support from the gears to where it enters the hotend. I am using this extruder (http://www.thingiverse.com/thing:728158) but i may work with others also.To install this part the stepper motor and filament must be removed. After the motor has been removed the support piece can be placed directly on top of the hotend. reassemble with part in place and then reload filament. I also drilled out the hole in the guide to give a smoother hole to hopefully prevent friction against the filament. Good Luck!