I bought this to check all my old cables, and also to check all the connections at church where I play. The best part is that it has two parts, so you can really check the signal of the cables running through the whole room.
The setting and manual on the other hand is a little bit clumsy. I had to find out myself what works and what doesnt, I checked mainly XLR / jack connectors. Out of 50 connections I was able to identify one cable that was not working properly, all the others looked fine, according to the tester.
The battery doors are very very difficult to operate, the battery space is really tight, but I found the way (without braking the door). Firstly place the battery, then lay the cable along the edge.
My small piece of advice - if not using it for longer time - take out the batteries..