They are made a little rough on the non-essential fit and finish but all seem to work well enough. I use one of these dedicated to every drill I use. They are cheap enough to keep setup for when I need them.
I use it in my mini lathe and mini mill and have been able to utilize much more space on the lathe and the mill has a lot more z space than with the jacobs chuck for sure.
Using this tool holder so I don't have to have so many CAT50 tool holders. Also bought a set of ER 40 collets in 1/8 so changing end Mills is a breeze. Beautifully machined tool holder and collet nut. Works great!
Lisa 
