4mm Screwdriver Socket Bits - M2, M2.5, M3, M4, M5

Adapt any precision screwdriver that takes 4mm bits into a tiny portable socket driver! Great for holding and tightening nuts, especially with an electronic screwdriver.

The stem has a hole for an optional M2 screw, letting you add a magnetic screw to hold them securely. Scale them up a little bit in the slicer to make them press-fit instead.

I tested M2 and M3, they work great. I also tried M5, but it's really the upper bound, the print is likely to crack if torqued down tight at those sizes. But for a quick hold-down job it's still fine.