This design is a conjunction of tools in a reduced size by be used for any person, have the most common size of tool: Wrench for 15 and 10 mm. Spoke key. Can hold three driver bits most used on your bike, and you can used like screwdriver only with change the bits.
I recomend use filament like NYLON,Taulman PCTPE, PET, HIPS and ABS. And fill 100%, because you will print tools and need a good mechanical capacity.