Just a simple 1/4" drive thumb driver. Nothing fancy so it doesn't ratchet, but it comes in handy. I made is mainly to use when I change out print nozzles.
The version in the picture was made with 0.8 mm nozzle, 2.3mm walls with a 30% infill.
In case you were wondering, it fits perfectly. Didn't have to do any finishing on the driver end.
0.8 mm nozzle and 2.2 mm walls (including top and bottom)