Biohazard Knob
thingiverse
Just added an outer ring with ridges. I've enjoyed using it as it was but sometimes the knob would try to grab wires and the ends were a bit sharp on my hands so I tweaked it a little.
Download Model from thingiverse
With this file you will be able to print Biohazard Knob with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Biohazard Knob.