David 4 This device seems to work pretty well, my only issue is the little retention ball bearing in the tool holders. The steel ring that holds the difference bits has a locking bearing the puts pressure on them, so the do move. They do not work on mine, in fact, they do not move at all. I had to hammer them into their detent so I could install the bits. Now the lock bearings are flush and useless, but the bits seat flush now. If I didn't take this step to make it work, I would have ask to return this tool and request a refund. Other than that, it's a good tool.