Update 20190829: I reworked this holder. You no longer need to use supports when you print it. I made it thicker and longer to prevent larger keys from breaking the holder
I created this hex bit holder to work with my Slim Packout Bins for Milwaukee bit holders, but they also work in the original Milwaukee bit cases.
This holder is made specifically for the Eklind Metric set with 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, 5 mm, 6 mm, 8 mm, and 10 mm keys, but it should would with most metric sets.
I've already broken the hole for the largest key, the holder is going to have to be thicker.
If you are using PET-G I recommend a non-overlapping fill like gyroid.