Review on Convenient 9V Battery Case Holder with Cover and ON/OFF Switch – Pack of 4 by Gent Dobson

At least 2 stars. It works. I think it deserves this rating because it's not a very good design. The case is too big so the 9V will pop out fairly easily. The bottom of the power supply is on the opposite side where you open the case, making it difficult to place when using for a DIY project. And finally, the 9V connector is also difficult, there is no space or corner to easily insert it. A popping battery is easily fixed by applying thick tape or foam padding to the bottom. Aside from that, to be honest the design is silly and annoying. But they all work.