helps guild the flexible filament like filaflex or ninja flex through the extruder into the hot endi printed it with 80 percent infill most likely ended up being 100% due to the small size also i printed it out of nylon hoping nylons properties would come into play of being low friction, it was difficult due to the fact that nylon stays gooey between layers and i don't know how to put a min time between layers so i printed out 4 of them to fix that issue, (i broke 1 trying to install it because i forgot to pull the filament out, or remove the bolt that i made a clearance hole for the socket head cap ) also rotate in x 90 deg to print it out easily. may need cleaning up or small about of trimming to allow clearance for moving parts it does work i have been printing with filaflex and haven't had any issues