The tools are 3D printed in metal. The designs are excellent and the tools work quite well. I’ve been using them for at least six months and haven’t had any problems.
I got the bit holder, the T-Shank saw blade holder, and the scalpel holder. They more than make up for what they replaced, except for the blades. Since I always carry both a plain edge and a serrated blade, it’s all a trade up.
It provides a much better grip and the curve give it a lot more leverage. I’ve been surprised at how much more effective it is than straight bars of a similar size. (This one was made by Teale Designs on Etsy.)