Built and mixed from many other fan parts. FOR 40 mm FAN and gregs extruder. I recommend printing with PLA 1.75 at 0.20 layer height and 33% infill. I used kisslicer but prints well with slic3r too. IMPORTANT: You'll need to glue the two tinny parts in order to adjust and fix the angle needed for your printer. UPDATE: Uploaded version 4 STL files, improved.Recommended print for kisslicer: 3 perimeters per layer 0.20mm layer height (no more than 0.30!) set infill between 20 and 50% (recommended 33%) My tests worked fine with 1.75mm PLA and 40 mm fan. This is a fan mount for 40mm fan and gregs extruder.