Bit Handle - Double Ended - 4mm bits

thingiverse

This is a good double-ended mini (4mm shank) screwdriver bit holder. Rather than keep swapping the bits in-and-out of a single holder or screwdriver, I keep my most commonly used bits in these holders. The bits slip-fit tightly. If they're loose for you, scale the holder up or down slightly to fit. The bits may loosen after a while; either print a new holder or use a dab of glue to hold them in place (you can always yank 'em out later). You can scale the length longer/shorter somewhat to adjust for hand size. They're hexagonal so they won't roll around. Small so they're easy to carry, but thick enough to apply a bit of torque. They're short enough to spin easily in your fingers for quick rotation. Double-ended so you don't have to have so many of them. You can mark them with paint or tape (as in the photo) to help distinguish the bits in them from a distance. These are for quick assembly/disassembly. Not meant to apply a lot of force, it's just plastic. If you need to really reef on something, get a metal bit holder.