I 3D printed a couple and use them regularly. They really make the whole thing foolproof.
I sometimes have trouble with draws, especially bubbles with a U-100 syringe. I have even bent a needle trying to hold everything steady while working the bubbles out, so I looked around to see if anyone made a holder to simplify things. I came across a few different versions people designed. They vary but basically keep the vial and syringe steady during the draw. Has anyone here tried one of these tools? I wonder if they really simplify drawing or end up being more hassle than they are worth.