This bit holder can be used as a screwdriver once you plug a bit and acts as a wrench too..
It was inspired from chris_e Repkey (http://www.thingiverse.com/thing:5654) but can be customized (hole size, thickness, nut size, text, ...) to your needs.
A must have for DIY activities or simply for your own printer :-)

Ready to print.

There is no need for support.
In case the holes don't match exactly the bit size, you can easily adjust them with a hot gun.