This is a relatively simple bit holder for C6 screwdriver bits, used for electric screwdrivers and other multitools.
You will need OpenSCAD to change the size and the embossed text, but it's pretty easy, you can just change the arguments to the module calls in the bottom of the file.
It's a single print with embedded magnets (cylinder shaped magnets with a diameter of 10 mm and a height of 4 mm), that needs to be inserted mid print, and end up being fully encased in plastic for a good protection against the elements.
I paused the printer at 13 mm, which is right before the magnets are covered, but check the layers when you slice, it might be a little higher if you use a raft or similar.
In one end, there is a hole to mount a small nylon coord (~3 mm diameter fits well) and the idea is that the ends are crossing in the middle of the printed part, and the ends of the nylon coord are then melted with a lighter so that a blob is formed to prevent the coord loosening. The strap plugs needs to be put on the nylon coord before melting the ends. They are used to cover the melted ends and should be snug fit, so no need for glue.
It's a little tricky to make the white lettering pretty, but I have used a white acryllic pen and isopropyl alcohol to whipe off the excess, and you will probably have to repeat it a few times to get a good cover and not too much outside the letters. If the print have a very smooth surface, it's probably a bit easier.