Tensioner Knob

Tensioner knob for M3 Screws/bolts.
Intended for use with belt tensioners, extruder tensioners or generally anywhere you would rather use your hand than a screwdriver.
Ensure that you print it the correct way up, there is a 1 layer thick solid section to support the hole. It is otherwise symmetrical.
Insert a M3 nut in one side, if you do not have hex head screws, and tighten all the way to the end.

Version 1 can be found here: http://www.thingiverse.com/thing:561529