Barrel Extension Prototype files

Prototype files for a base for barrel extensions, currently only comprising of the barrel ring clip and a ball end nub. I have seen a similar file but it seemed a bit convoluted so I decided to create my own version that should be much more simple. The nub if it wears down should also be much easier to replace.

You will need 1 x m2 4mm long screw, button head preferable to attach the nub from the top side.