Performance Tool W3207 4-in-1 Pocket Screwdriver (Phillips & Slotted)

I bought two of these to use, as an industrial equipment maintenance tech for fine adjustments and removal of small screws for pneumatic solenoid valves. It works great for the purposes I bought it for, the only negative review I have is that both of the ones that I have, won't hold the driver bits or the part the bits fit into. If I'm working on something either part will just fall out. Like the ball plunger that is supposed to hold the bits in, doesn't due to there not being any kind of groove for it to lock into it. I bought these, as the smaller drivers are not used too often for me, and not worth the higher cost of a nicer setup.. Will be checking out another one next time I'm in town, just in case I got some from a bad batch.