The only reason I bought this device was that our Cisco switches detect POE connections without using a bulky IP phone. I needed this to quickly trace sockets to switches. Our switches don't register connections, but they do register performance changes on ports. This device causes the log to show "Power on" and then "Power off". That's all I had to do and he's doing it. It has other features that seem accurate when tested. This unit isn't super premium and I'm not sure how long it will last, but for the money. It's good enough to serve my purpose. The instructions are fine. Nothing remarkable.