This is a simple top-mount filament guide to fit Prusa i3, with the ~5mm acrylic frame. Print it upright as in the STL, then file the edges of the forks as needed. Should press right on to the frame.
Since my all-in-one extruder (https://www.thingiverse.com/thing:2284219) sticks up pretty high, I needed to make a filament guide that sits up equally high to complement it.
Printer: Prusa i3
Rafts: No
Supports: No
Resolution: 0.2 mm
Infill: 40%
Notes:
Printed with Atomic "Starry Night" PLA (v1), with Slic3r's "triangles" infill pattern.
The author marked this model as their own original creation. Imported from Thingiverse.