Extruder Shaft Spinner Knob

This is a small spinner "knob" that fits on the extruder shaft of the Monoprice Select Mini printer, with a slot that can hold other spinners. It would probably fit any other printer with a 5mm shaft. It is not keyed and does not grip well enough to manually rotate the shaft.

I had printed the "Gyro Spinner for MPSM" by itsonlym3 (http://www.thingiverse.com/thing:1974191), but the cylinder did not fit on my extruder. I decided to design my own adapter, that could be a small spinner on its own