Holes are 3.5mm diameter. I use #4 screws for wood.
I spent a lot of time deciding which ratcheting screwdriver I wanted and this is the one I picked. So naturally it needed a proper home.
If you have a bahco 808050 this holder will fit it perfectly. I included the step file to edit for other drivers if needed.
I printed mine bottom down with support for aesthetic purposes but I think it should be printable without supports with the side opposite the opening on the bed. Never tested this though.
The author hasn't provided the model origin yet.